Joe Jusko has created some outstanding art for the E. R. Burrough's series "Warlord of Mars" and much of it features the green-skinned four-armed Martian giants known as Barsoomians.
They certainly are something puny humans would have a hard time besting in a one-on-one fight. Yet, Burroughs' character, John Carter, takes them on like the fantasy hero he is.
I hope that after the film of "John Carter" is released next March we start getting some fan fiction and art devoted to Barsoomian-Human inter-species intimacy. Sex with four large muscular arms to hold you and play with you sounds incredibly titillating.