I will make my answer in the form of a question...
Is it Human or human?
Depends on whether or not the word begins a sentence, AFAIK. I think deathclaw is one word, while the others are separated words, as rad scorp is a type of scorpion, and super mutant is a type of mutant. Although, with dogs, the type, such Doberman, IS capitalized. Who says Doberman dog though? Meh, no caps on any and only deathclaw as one word would be my vote.