Tierno's Squirtle is
Tierno's starter Pokémon given to him by
Professor Sycamore. It was first seen in the anime battling against a Roubushin which it showed off its dance moves and jumping power.
During the first day of the Pokémon Summer Camp, it was matched up in a battle against
Ash's Froakie in a Water against Water battle. Its dodging rhythm made it too hard to hit and it ended up defeating {Char=Ash_Froakie}}.
Tierno's Wartortle is the evolved form of
Tierno's Squirtle. It evolved sometime after battling
Clembot at the Miare Gym and before meeting
Ash Ketchum in the forest for a training double battle.