This Mamoswine is an Ice/Ground-type Pokémon owned by Dawn. It was the fifth Pokémon captured by her as well as her sixth Pokémon in all.
Dawn caught Mamoswine as a Swinub. It was very glutinous, but friendly to Dawn.
In later episodes, it evolved into Piloswine, then into Mamoswine. Since Mamoswine evolved, it stopped listening to Dawn's orders.
During a battle against a wild Aggron, Mamoswine got injured, but got healed in the process. Since then, Mamoswine obeyed Dawn again.
Mamoswine trained with Piplup as a partner once, but it did not go well. The same went for Pachirisu. Dawn's Cyndaquil was the one to work well the best with Mamoswine. During their practice battle against Zoey, Zoey's Kirlia used Psychic to control her Leafeon's Magical Leaf, defeating both Mamoswine and Cyndaquil.