It's hard to believe that Toad, a recurring X-Men villain, hasn't made it in yet. While he's hardly as popular as Magneto, he's consistently been in comics and cartoons and movies for over 50 years at this point. The same could be said to a lesse extent for Pyro, and Avalanche, which makes a Brotherhood of Evil Mutants season one I'd like to see. Certainly more than a rehashed version of existing characters, and Toad is certainly less obscure than the Dragon of The Moon.