Sid

Sid is a heartless swarm of nanobots projecting the image of a rather starved and skinny bird. He could look like anything he wanted, but he likes his consistency.
He's a demon of sorts, worshipped by some robots and on the occasion summoned by them to do some dirty work.
While being a swarm of nanobots means he isn't very strong physically, he's still a terrifying force that can simply enter your body and kill you by ruining your insides. And maybe a billion other things if you're a robot.

Currently possessing Rabaramsho.
He's also a little afraid of Qupizo, because Qupizo probably knows how to perform a robot exorcism.

Character playlist:
Metallica - Slither