Iris' Axew

Iris' Axew  was the first Pokémon Iris was revealed to possess, and appeared alongside Iris in In the Shadow of Zekrom!.

Biography
Axew first appeared in BW001: In The Shadow of Zekrom!, alongside Iris, where they witnessed Zekrom's thundercloud over Nuvema Town.

He was fully introduced in BW002: Enter Iris and Axew, where he was the first Pokémon that Ash scanned with his new Pokédex, although he was aiming it at Iris' hair and so wondered why it looked nothing like the Pokédex image. Axew struck up a fast friendship with Ash's Pikachu, showing that he is very friendly. Axew is shown to have a close bond with Iris, as she tried everything to rescue him from a Sandile's mouth in BW003: A Sandile Gusher of Change.

According to Cilan in BW005: Triple Leaders, Team Threats, Axew and Iris have perfect compatibility. He later watched Ash's battle against the three Leaders of the Striaton Gym. In BW006: Dreams by the Yard Full!, it is revealed that Axew's dream is to evolve into a Haxorus.

Axew has some childish traits about it, as shown in BW008: Saving Darmanitan From the Bell!, where he starting fighting with Pikachu because he thought Pikachu had stolen his food. It is shown in BW009: The Bloom Is on Axew! that Axew is a weak battler, as he cries even when hit by weak attacks. Despite this, he has a powerful attack, Dragon Rage. However, he hasn't quite mastered it yet, so when he uses it, the attack accidentally explodes everywhere instead of being fired at an opponent, which Ash and Cilan teasingly call "Dragon Sneeze", much to the annoyance of Iris. It is also revealed that Iris obtained Axew from a matriarch in her hometown (possibly Opelucid City) when he was a baby.

In BW036 he battles Georgia's Beartic but is easily defeated

After being told that he will be like a "big brother" to the Pokémon inside Ash's egg, Axew began dancing happily and accidently knocked the egg down a hill. It was saved by Pikachu before any harm could come to it. After seeing how aggressive Scraggy was, Axew kept his eye on it and was the first to realize when he had wandered off. After Scraggy was paralyzed by a Galvantula, Axew helped Iris find a plant that would cure him. Axew battled Scraggy the following day, with the battle ending in a draw. They had a second battle in BW020, but it ended after Axew attempted to use Dragon Rage.

In BW030: Dragon Master's Path! Axew learned to master Dragon Rage in a battle against Team Rocket.

In [http://pokemon.wikia.com/wiki/BW044:_The_Club_Battle_Finale:_A_Heroes_Outcome! BW044: The Club Battle Finale: A Heroes Outcome!] Iris used her Axew against Luke's Golett at the Don George Tournament and during the battle Axew learned the move Outrage which helped Axew win the battle.

Mystery Egg event
A Japanese event would randomly distriubute in-game representations of Cilan's Pansage, Ash's Pidove and Iris' Axew. Axew is always male and always has the ability Mold Breaker.

Trivia

 * Axew has some similarities with Ash's Gible, namely the way in which Axew charges up his Dragon Rage is very similar to Gible and his Draco Meteor.
 * Axew and Gible both had difficulty mastering these Dragon-type moves.
 * They are also both part of a three-stage evolution that retain their typing throughout all three forms.
 * Axew is also similar to Ash's Caterpie
 * Both expressed that their desire was to evolve into their final form.
 * Unfortunatley, Axew may never evolve because the pokemon that are usually traveling with trainers while not being in their pokeball tend to not evolve. Examples of this are Ash's Pikachu, Team Rocket's Meowth, and Dawn's Piplup
 * Axew is a tiny bit like Misty's Togetic '
 * Iris carries Axew around in her hair and Misty carries Togepi around in her arms.
 * They also both belong to the female character in the group.
 * Axew has been revealed to have a crush on Iris' Emolga, as confirmed by Iris herself.