Snowy

This Alolan Vulpix, nicknamed Shiron, is an -type Pokémon owned by Lillie. It is her first Pokémon.

Personality
Shiron, when hatched, is a very curious and naive Pokémon due to its young age, but it also started off as a bit shy around others, and even gave Ash its version of a cold shoulder when he tried to pet it by freezing him with its Powder Snow. Shiron took an instant liking to Lillie, probably seeing her as a parental figure due to her taking good care of it as an egg. It also shows great bravery when trying to protect Lillie from Team Rocket. Shiron, at first, didn't want to play with the others, but eventually warmed up to them in the end.

Yet, sometimes Shiron can be naughty by freezing Lillie into an ice statue and showed its affection.

As an egg
Shiron, as an egg, was found by Principal Oak near Mount Lanakila. It 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 it.

Ever since then Lillie has been taking good care of the egg and fearing for its safety. The egg was later watched by Professor Kukui who was telling it to hurry up and hatch so it 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 it, after it hatches.

As Vulpix
The next day, the egg started to hatch. To everyone's discovery, Lillie named the egg "Shiron" while she was taking care of it. The egg cracked and hatched into a white Alolan Vulpix. After the egg hatched, the egg that Ash brought from Kanto hatched into a red Vulpix. Alolan Vulpix, Shiron, became spooked when Ash tried to pet it and froze him and Rotom. Samson's Vulpix, however, helped Shiron become friends with the other Pokémon. Principal Oak told the students they could raise the Alolan Vulpix while he raised the Kanto Vulpix. Ash and everyone agreed that Lillie should be its trainer, since she took care of it the most and had a nickname for it. Professor Kukui gave a Poké Ball for Lillie to catch Shiron in, but she missed and hit Ash before hitting the ground. Out of curiosity, Shiron touched the button and went into the Poké Ball and jumped right in with everyone seeing that Shiron chose Lillie to be its trainer on its own. Lillie let Shiron come out of its Poké Ball, then she tried touching it. However, she was unable to do it, much to Shiron's sadness. After everyone left, Lillie decided to walk home, so she could bond with her first Pokémon. While walking Lillie told Shiron that she didn't know why she couldn't touch it or other Pokémon, but she told Shiron that she loved it and would change herself. Lillie took Shiron to a malasada donut shop to try some malasada donuts, which it liked a lot. While continuing to walk, the two were ambushed by Team Rocket, who wanted to steal Shiron. Due to Lillie's quick thinking and Shiron's Powder Snow, they were able to get away before hitting a dead end. Team Rocket caught up to them; Shiron did the best it could to protect Lillie but it got hit by James' Mareanie's Sludge Bomb as it went over the building. Lillie jumped to protect her Pokémon and held her Vulpix. Lucky for them Ash's Rowlet was able to catch them in time using its Leafage to save them. Landing safely with Mallow catching her and happy that her Pokémon was okay, Shiron froze Team Rocket with Powder Snow. Out of nowhere, Bewear showed up and took them away again. Ash and Mallow were happy Lillie could touch her own Pokémon which made both of them delighted. The following day, everyone was glad that Lillie could hold Shiron with no problem. Lillie told Shiron that the other Pokémon are its friends. Shiron greeted everyone by jumping with joy with the other Pokémon, then it jumped back to Lillie's arms. This encouraged Lillie to touch other Pokémon without fear one day.

Shiron was seen playing happily in a bubble made by Popplio. Then Lillie tried to help Ash to distract Kiawe by telling Shiron to imagine it played with Rockruff a while ago.

Trivia

 * Shiron is the first Alolan Form Pokémon owned by a main character.
 * It is the fourth nicknamed Pokémon to be owned by a main character, the other three being Growlie, Caserin and Luverin.