9. Castform
Another pet peeve pokemon, Castform is known as being the pokemon with boobs or testicles. Its base form looks like it has balls underneath its chin. It's also known for having the gimmick of being able to transform into different forms depending on the current weather in the region visited by the player. That, combined with the fact that Ruby and Sapphire were the first games featuring weather, allowed for good advertising of the capabilities of the new GameBoy Advance handheld. Now, in terms of relative strength, Castform is not weak – it's got stats around the levels of Dragonair and Linoone. It does, however, learn some fairly powerful moves, including Weather Ball, which changes effect depending on what weather it is.
