my goodness this was fun !
this alien person is somewhat lizardlike, and i imagine the markings on their skin function as an identifier to other members of their kind. not sure if they lost their arm or never had one, but they wear a false one that is removable but functions about as well as a regular arm.
this is 45% of the full size - if this wins, i can provide a full-size version privately, but i don't want to post it publicly.