Snowy, when hatched, is a very curious and naive Pokémon due to her young age, but she also started off as a bit shy around others, and even gave Ash her version of a cold shoulder when he tried to pet her by freezing him with her Powder Snow to keep everyone away from her. Snowy took an instant liking to Lillie, due to seeing her as a parental figure because she took good care of it as an egg. After spending most of the day bonding on the day she hatched, Snowy and Lillie not only formed an unbreakable partnership but they also became best friends. Much like Serena's Sylveon, as a Eevee, was comfortable with Clemont's Bunnelby and their friendship, Snowy felt comfortable and is best friends with Ash's Incineroar, due to also not being entirely too hyperactive and energetic as Lillie and Snowy herself. Also, Snowy easily formed a close friendship with Ash's Pikachu, Mallow's Tsareena, Sandy and Shaymin. Snowy is even good friends with the rest of the Pokémon owned by her Trainers friends and with Gladion's Pokémon as well.
She also shows great bravery when trying to protect Lillie from Team Rocket. Initially, Snowy didn't want to play with her trainer friends Pokémon or be friends with them either at first but eventually warmed up to them in the end. Snowy also had trouble opening up to other people, but began to warm up slowly after staying with Ash and his Pokémon temporarily.
Snowy can also be naughty at times, such as freezing Lillie to show her affection.
Despite her confidence, Snowy is shown to be uncertain about evolving when Lillie sees that Snowy isn't ready to evolve yet when she shows her the ice stone and Lillie keeps until she is ready.
As an egg
Snowy, as an egg, was found by Principal Oak near Mount Lanakila. She was compared to a regular Vulpix egg brought to Alola from the Kanto region by Ash Ketchum. Oak took care of the Kanto Vulpix egg, and left the Alolan Vulpix egg in care of Lillie and the other students. Lillie decided to take the egg home to try and get over her fear of touching Pokémon, and after a wild Salandit tried to eat the egg, she managed to face her fear and held the egg to protect her.
Ever since then Lillie has been taking good care of the egg and fearing for her safety. The egg was later watched by Professor Kukui who was telling her to hurry up and hatch so she could play with the other Pokémon.
Later, the egg was in Lillie's care while the others competed in the race. During the race, she began to notice that the egg starting to glow. Mallow proposed Lillie should enter the race with her, after it hatches. The next day, the egg started to hatch. To everyone's discovery, Lillie named the egg "Snowy" while she was taking care of her. The egg soon began to crack.
As VulpixThe egg hatched into a white Alolan Vulpix. After hatching, Snowy was very happy to finally meet Lillie, who is also happy to finally meet her as well. After the egg that Ash brought from Kanto hatched into a red Vulpix, Snowy used Powder Snow on Ash and Rotom, after Ash spooked her when he tried to pet her. Snowy didn't want to play with other Pokémon but Samson's Vulpix encourage her to come down from the desk to play with them and Ash tells her that they all want to be her friends. Snowy was nervous on being Kiawe's Turtonator back then hears Principal Oak tell the students that they could raise the Alolan Vulpix while he raised the Kanto Vulpix. Hearing how nervous Lillie was when her friends all decided that she should be the Alolan Vulpix trainer since she been taking care of her this whole time and had a nickname for her, Snowy went over to Lillie and encourages her to not be nervous. Snowy was asked by Lillie to be her partner which she accepts then Professor Kukui gave a Poké Ball for her to catch the Alolan Vulpix in. Out of curiosity, Snowy touched the button and went into the Poké Ball, after the Poké Ball missed her and hit Ash by accident, and jumped right in with everyone seeing that she also chose Lillie to be her trainer on her own. Snowy was let out of her Poké Ball by Lillie, who tried touching her. However, Snowy became sad when Lillie was unable to touch her. After everyone left, Snowy and Lillie decided to walk home so they could bond together. While walking, Snowy hears Lillie explained that she doesn't know why she couldn't touch her or other Pokémon but she told her that wanted to do something about it because she deeply cares about her a whole lot which makes her very happy. Snowy went to a malasada donut shop with Lillie to try some malasada donuts which she liked a lot. While continuing the walk, Snowy and Lillie were then ambushed by Team Rocket, who wanted to steal Snowy. Due to Lillie's quick thinking and Snowy's Powder Snow, Snowy and Lillie were able to get away but Team Rocket caught up to them. Hitting a dead end, Snowy did the best she could to protect Lillie but she got hit by James' Mareanie's Sludge Bomb which blows her over the building. However, Snowy was saved when Lillie, who wanted to protect her partner and her friend, jumped after her and held her in her arms. Snowy and Lillie landed safely when Ash's Rowlet used its Leafage attack to help break their fall. Landing safely with Mallow, who's been following her with Ash, catching Lillie and happy that her Pokémon was okay, Snowy froze Team Rocket with Powder Snow. After Team Rocket got taken away by Bewear, Snowy jumps to Lillie, who realizes that she could touch her own Pokémon, and both of them became delighted. The following day, Snowy and Lillie walk into school as they greeted everyone, who were very glad that Lillie could hold Snowy with no problem. Snowy was told by Lillie that the other Pokémon are her friends. Snowy greeted everyone by jumping with joy with the other Pokémon. Seeing how determined her trainer is to touch other Pokémon without fear one day, Snowy gives her full support to her partner and her best friend when she jumps back into Lillie's arms.
Snowy was seen playing happily in a bubble made by Popplio. Then Lillie tried to help Ash to distract Kiawe by telling Snowy to imagine it played with Rockruff a while ago. Snowy helped Lillie and her classmates rescue Ash and Litten from an angry Palossand by freezing it with Powder Snow, while Ash's Pikachu and Lana's Popplio searched for its missing shovel. Snowy was unable to freeze it, but Lillie and her friends started blowing a wind. This helped Snowy, who managed to freeze Palossand. Yet, it soon grew exhausted, though Lillie hugged it gratefully. Snowy was then seen playing with its Pokémon friends with Charjabug at the front. Hearing Gladion was in town, Lillie sought him out. She showed that she could touch Snowy; Gladion bluntly replied she should take care of her. Since Gladion didn't want to return to the mansion, he left Lillie and Snowy.
Snowy played baseball, being on Kiawe's team as the Left Fielder. She helped Lillie to catch the ball and she was praised by her, who was thankful. During camping, Snowy playfully froze the pot of curry that Lillie was cooking, which caused Litten, who was the one to light up the fire, became extremely outraged. Later, Snowy's energy was drained by a Morelull. Even after Snowy was fed, the Morelull appeared once more and put everyone to sleep, then drained more of their energy. However, Ash started eating the curry and let Morelull drain his energy to power it up. After Morelull was fed, the group followed Morelull, who joined the others of its kind to a giant tree. There, everyone watched as the Morelull evolved into Shiinotic. The Shiinotic Ash befriended came, thanking for taking the energy, then put the group to sleep. The next day, the group, including Snowy, woke up, and they didn't feel hungry, as the Shiinotic returned the energy it borrowed.
Before the class started, Snowy watched the other Pokémon as they were having a race around the room, that Pikachu won. Since Kukui had the class take a task to exchange Pokémon, Ash traded Pikachu for Lillie's Snowy. Snowy was saddened to be separated from Lillie, who went away with Pikachu. At Kukui's house, Ash tried to befriend Snowy by sending his Pokémon out. However, Snowy refused to eat, making Ash saddened and Rotom confused, as that was supposed to be her favorite food. Instead, Snowy went sleeping next to Litten. The next day, Ash noted Snowy had not eaten anything and proposed to go for a walk. Snowy became happy, and Ash ran off to the marketplace lady. There, Snowy saw how Ash's Pokémon were eating and Litten gave her a piece of fruit. Snowy started eating and liked the food, while Ash was thrilled he was getting to Snowy. The group came to the beach for training, where Ash told Snowy she could surprise Lillie by becoming stronger. Snowy agreed, and used Powder Snow to freeze a wave, which amazed Ash. The following day, before the class returned their Pokémon back, Ash proposed a battle with Lillie. Lillie agreed, and had Pikachu battle Ash and Snowy.
Olivia, who came to the Pokémon School, wanted to meet the heroes' Pokémon, and met Lillie's Snowy. Since the task was to mount on Stoutland and find treasures, Lillie was unable to do the former. With Kukui and Olivia's encouragement, Lillie noted how she did befriend Snowy and Pikachu, motivating her to go atop Stoutland, a task she succeeded in. At Kiawe's farm, Snowy was eating the Pokémon food mixed with the Moo Moo milk, and liked that food, which fascinated Lillie as a result.
Snowy and Pikachu helped the kids to search for Mallow after she ran away from home.
When the three boys were discussing about the Charjabug car race, their enthusiasm made the environment in the classroom too hot, so Snowy decided to help by freezing them.
When Ash and his Alolan friends went to Kanto, Snowy became ill after departing from the airplane, worrying Lillie. Brock came and offered to perform a checkup on Snowy, and upon doing so, deduced that she was suffering from motion sickness during the flight, and that she would recover quickly. During the visit to Prof. Oak's lab, Snowy encountered a Kantonian Ninetales, which befriended it. When a Jigglypuff emerged from the destroyed Meowth robot, Snowy slept upon hearing it sing, and had its face doodled on as a result. 
Snowy had a sleepover with the class at Kukui's house. Unfortunately, Lillie regressed after seeing Type: Null and made Snowy puzzled as she was unable to touch her again.That night, Lillie even apologized to Snowy because she saw how eager her hoped to get hugged. The next day, Lillie wanted to hug Snowy but she was still unable to do so, causing Snowy to become more confused. After Ash and Lillie were being teleported to several places by Nebby, Snowy, along with Pikachu, Ash and Nebby were attacked by Faba at the Aether Foundation secret labs by Psychic attack of Faba's Hypno. As Lillie finally overcame her fear after thanking Silvally, Snowy jumped up to Lillie's arms to give her best friend a hug, as she can touch her partner again, with Nebby and Pikachu coming as well, as she can also touch them too.
Snowy, along with Umbreon and Silvally, attempted to protect Lillie from getting attacked by Nihilego. But she watched in horror as Nihilego abducts her mother, Lusamine, and carries her into the Ultra Wormhole Faba opened.The next day, when Lillie and Gladion faced Totem Kommo-o, Snowy was sent out to fight along with Silvally and it helped to freeze the ground so that Gladion could retrieve the Fairy Disc. When a large boulder which fell from the top nearly hit Lillie and Snowy during their escape with Gladion and Silvally, they were rescued by Pikachu thanks to his Electro Ball.
Snowy, along with all of the gang's Pokémon, witnessed the Tapu Guardians perform and ritual and Nebby's evolution into Solgaleo. After travelling through the Ultra Wormhole, the group finds Lusamine fused with Nihilego. As the group chases after her, Snowy, with the help from Ash's Lycanroc, helps Lillie get through to Lusamine's Clefable and snaps it out of the Ultra Beast's mind-control. Snowy then witnesses Lillie talking some sense into her mother as well as Ash and Pikachu performing the 10,000,000 Volt Thunderbolt Z-Move as a final ditch effort to save her. After saving Lusamine, Snowy and the rest of the gang leaves Ultra Space and returns to the Pokémon world.
Snowy later attended Professor Kukui and Professor Burnet's wedding ceremony.
Sometime later, Snowy helped Lillie and her classmates complete several Ultra Guardian missions and helped Ultra Beasts return home.And in the process it meets a new friend who is also an Ultra Beast, Ash's Poipole.
Snowy later travelled with Lillie to Mount Lanakila, where it was founded by Samson Oak. Upon arriving there, Snowy sensed the presence of an Alolan Nintales. Once they found it, they meet up with Ninetales' trainer, Cerah. Cerah tells Lillie that she and Ninetales are preparing for the Pokémon Sled Jump Games and after giving a magnificent demonstration, Lillie decided to compete in the games with Snowy as well as learning Aurora Veil. After a few hours of intense training, Snowy manages to perfect the Aurora Veil move and makes a spectacular jump in the competition. But despite that, they weren't able to win, which Lillie doesn't seem to care.
Later, Snowy, Lillie, Mallow, and Sophocles got separated from the Kiawe and Ash during another trip to Mount Lanakila. The group found themselves in a cave full of Alolan Sandshrew led by one bigger than a normal one. They soon discover that the cave is being invaded by a rogue Tyranitar who is trying to take over the territory. Snowy and Lillie decides to step in and help the Sandshrew defeat Tyranitar. Using the same strategy Olivia used in Ash's Akala Grand Trial, Snowy powers up Sandshrew with its Aurora Veil and attacks Tyranitar with a Powder Snow and Metal Claw combination. Snowy and Sandshrew emerge victorious and sent Tyranitar packing. Snowy then witness Sandshrew evolving into Sandslash with the Ice Stone Sophocles found and felt speechless about it. Sandslash gives Snowy and Lillie an Icium Z as a gift for their help. Upon reuniting with Ash and Kiawe, Sophocles gives Lillie the Ice Stone his Charjabug found. Lillie then attempts to evolve Snowy, but it got scared and backs away from the stone, making the other sense that it's not ready to evolve yet. Lillie then decides to hold on to the Ice Stone in case of Snowy changes its mind when it's ready.
Later, Snowy befriends a messy-haired Eevee that came from across the sea to Alola. Snowy plays with her new friend until it was time for her to return to Lillie with her friends as they also needed to go back to their trainers. While in the car with Lillie, Snowy sees Lana, Ash, Sophocles and Mallow with their Pokémon outside the window which got her trainer to stop the car to let them out. Snowy greets her friends but she and Lillie realizes that Popplio was not with them. Realizing that Popplio went missing, Snowy and Lillie offer to help Lana look for her Pokémon. After meeting up with Kiawe, Snowy witness Kiawe and Ash's Rowlet search for Popplio through the air. Finding Popplio at the beach battling Team Skull, Snowy was very happy to see her friend Eevee again then witness his and Popplio teamwork in defeating Team Skull. Snowy was in Lillie's arm when her trainer and everyone explain to Kiawe, who arrived after Team Skull was defeated, about Eevee then witness her friend being nicknamed Sandy and caught by Lana.
Upon at arriving at Poni Island, Snowy helped Hapu with her chores around her house. Snowy later watched Ash's Grand Trial against Hapu. Snowy later participated in Poké Golf. Snowy participated in a movie with her trainer.Forest Pokémon Café to help Oranguru serve hungry Pokémon, Snowy and Lillie helped as extra waiters in Aina's Kitchen. Due to the countless customers who had come to dine, Snowy and Lillie were worn out as a result when Mallow returned. Also, Snowy and her friends were excited that their Trainers all have Z-Rings. At the school, Snowy and Lillie were practicing their poses for their Z-Move, along with their friends. At Lillie's Mansion, Snowy was then seen having lunch with her friends.
At the Alola League, Snowy was used in a Battle Royal during the first round and one of 16 competitors to move to the finals. Snowy was then used to battle against Gladion's Umbreon, despite using its ability Snow Cloak to avoid Shadow Ball and using Subzero Slammer, it was defeated by Umbreon's super effective Iron Tail, which caused Lillie to lose the League.
At some point during the Ultra Beast crisis, Snowy helped join everyone to defeated one of the Guzzlord at the Manalo Conference. 
- Snowy is the first Alolan Form Pokémon owned by a main character.
- She is the fourth nicknamed Pokémon to be owned by a main character, the other three being Growlie, Caserin and Luverin.
- However, Snowy is the first of the two major nicknamed Pokémon to be in the same series airing, second being Sandy.
- Her English nickname is obviously named after the word "snowy", in reference to her fur being as white as the driven snow. Her Japanese nickname comes from "shiro" (which means "white"), and "koron koron" (which means "to roll around"), as stated by Lillie in "Getting to Know You!"
- She is the only Pokémon where she was hatched as an egg and caught in a Poké Ball in two different episodes.
- As shown in the segment for SM035 and SM104, Snowy detests Spicy food. She is shown to prefer sweet food such as pancakes and yogurt in the latter.
- ^ Pokémon Sun and Moon Promotional DLC Event Manual
- ^ SM008: Lillie's Egg-xhilarating Challenge!
- ^ SM009: To Top a Totem!
- ^ SM010: Trial and Tribulation!
- ^ SM012: The Sun, the Scare, the Secret Lair!
- ^ a b SM013: Racing to a Big Event!
- ^ SM014: Getting to Know You!
- ^ SM017: Crystal-Clear Sleuthing!
- ^ SM022: A Shivering Shovel Search!
- ^ SM027: A Glaring Rivalry!
- ^ SM028: Pulling Out the Pokémon Base Pepper!
- ^ SM029: Lulled to La-La Land!
- ^ SM030: The Ol' Raise and Switch!
- ^ SM031: The Island Whisperer!
- ^ SM032: Treasure Hunt, Akala Style!
- ^ SM033: Big Sky, Small Fry!
- ^ SM039: Mallow and the Forest Teacher!
- ^ SM041: Mounting an Electrifying Charge!
- ^ SM042: Alola, Kanto!
- ^ SM043: When Regions Collide!
- ^ SM048: Night of a Thousand Poses!
- ^ SM049: Mission: Total Recall!
- ^ SM050: Faba's Revenge!
- ^ SM051: Family Determination!
- ^ SM052: Revealing the Stuff of Legend!
- ^ SM053: Rescuing the Unwilling!
- ^ SM054: 10,000,000 Reasons to Fight!
- ^ SM055: The Professors' New Adventure!
- ^ SM061: A Mission of Ultra Urgency!
- ^ SM069: Rise and Shine, Starship!
- ^ SM078: Twirling with a Bang!
- ^ SM085: The Long Vault Home!
- ^ SM114: Beauty is Only Crystal Deep!
- ^ SM124
- ^ SM067: Love at First Twirl!
- ^ SM060: Getting a Jump on the Competition!
- ^ SM080: Not Caving Under Pressure!
- ^ SM090: Securing the Future!
- ^ Where is Eevee Going?
- ^ SM099: We Know Where You're Going, Eevee!
- ^ SM107: Run, Heroes, Run!
- ^ SM109: A Grand Debut!
- ^ SM110: Keeping Your Eyes on the Ball!
- ^ SM113: This Magik Moment!
- ^ SM116: The Secret Princess!
- ^ SM121: A Recipe for Success!
- ^ SM122: Spying for the Guy!
- ^ SM123: A Fiery Training Camp Trick!
- ^ SM127: Chasing Memories, Creating Dreams!
- ^ SM129: Battle Royal 151
- ^ SM131: The Battlefield of Truth and Love!
- ^ SM140