Deathclaw

"Deathclaws. Good grief. They're once Jackson's chameleons before they get to become large, agile and strong mutated species through genetic engineering, other than nuclear radiation. Reminds me of these skin-peeled retards who dare try to eat my flesh and bones like zombies... and even raiders, folks without any injuries, but have a lust on resources. Even super mutants. Idiots who wanted to destroy us too."

--Su Ji-Hoon, A Brave New World

Deathclaws are a large, agile and strong species of mutant Jackson's Chameleon created through genetic engineering, with the addition of DNA of various other species. However, due to mutation, most of them have lost their color-changing ability.