So I'm relatively new to the fallout series and I was curious as to what a Deathclaw actually was. So I looked it up. Reading through the wiki, I discovered something. Deathclaws are actually mutated forms of Jackson's Chameleons! Luckily, however, their color-blending ability was destroyed through the mutation. Can you imagine if they could still change colors and virtually be invisible?! The idea scares the spit out of me...

i think in a..... less canon game, they had stealth deathclaws. yup, heres the wiki for it.

http://fallout.wikia.com/wiki/Experimental_deathclaw#Chameleon_deathclaw