Blastoise's design is heavily influenced by turtles and tortoises. The cannons likely draw inspiration from the concept of a mobile tank or battleship.

Blastoise is notable for being the final evolution stage of one of the original starter Pokémon, along with Venusaur and Charizard. It has a Mega Evolution, available in Generation 6 games and Pokémon Go; it also has a Gigantamax form available in Pokémon Sword/Shield, with an exclusive G-Max move, G-Max Cannonade.