Dawn's Mamoswine was the fifth Pokémon captured by Dawn in the anime, and her sixth Pokémon in all.
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.