Blastoise

The mythological roots are pretty much dropped completely when Wartortle evolves into Blastoise, making the turtles the most inconsistent of the original starters. Bulbasaur progresses through stages of symbiotic plant growth and Charmander evolves from fiery lizard to fiery dragon, but Squirtle grows itself a bigger, fluffier tail and then trades it in for...guns?

Blastoise's water cannons are its key feature, and they raise a lot of questions. They don't look at all organic, so are they metal? Bone? It always looked to me like they could retract into the shell, but I can't recall if we've ever seen that happen.