Squirtle is an Water Type Starter Pokemon of Pokemon Red, Blue, Green, FireRed and LeafGreen. In Pokemon Yellow X, Y, HeartGold and SoulSilver,he is recieved as a gift.
Squirtle evolves into Wartortle at level 16 and again at level 36 into Blastoise. In Pokemon X and Y, he can be evolved into a Mega Pokemon.
In Super Smash Bros. Brawl
Squirtle is one of the playable characters when you select Pokemon Trainer. He can use Hydro Pump, Withdraw, Water Gun and Waterfall.
In Subspace Emissary
Squirtle is the first playable Pokemon in the Story Mode after you defeat Pork from Earthbound.