I have been creating aliens species for a while now, and the idea of a sapient, tool-wielding, spacefaring civilization that doesn’t have arms as we know them excites me. I would like my aliens to have a scientifically plausible design.
For simplicity, relevance, and lack of acceptable concept art’s sake, imagine this species as being a cheetah with scales and hooves. I have been trying to design a way for them to have several “tails” that can each be used almost as well as a human arm. I designed a sort of arm-like appendage that had its own shoulder-blade-pelvis structure in the rump, and the “fingers” of that arm were long enough to reach the front of the creature. This is obviously doomed to fail, and I need a better solution. Edit: I had also tried to split the spine into several independent prehensile tails which was even more doomed to fail than the arm-fingers idea. Also, the arm-fingers idea is too similar to actual arms and fingers for my liking.
I have seen tentacles be suggested in other questions over prehensile tails, and I am inclined to agree, but how to place several of them on the body escapes me. These creatures are speed based apex predators and as such must be relatively lightweight and aerodynamic. They will use their limbs for hard manual labor, fighting, and tweaking minute computer parts. How many of these limbs are needed is up for debate, but ideally more than one (In concept art I am fond of there being 4 or 6) so more complex tasks can be performed with the limbs working together. I have also become VERY attached of the idea that they can create a whip-crack noise with their tails, but I fear that may not be possible. Important note: they can turn their heads like owls and are remarkably flexible, so the manipulation limbs being located further back is not as much of an issue