Doctor Ub'x is a fictional character in the DC Universe. He first appeared disguised as the villain Polestar in Green Lantern Corps #201 (June 1986), then disguised as the villains Truk, Malignon, and his true form in Green Lantern Corps #202 (July 1986). Ub'x was named after Walt Disney animator Ub Iwerks.[1]
Doctor Ub'x is a H'lvenite, a rodent-like alien originating from the planet H'lven in Sector 1014. He attempts to conquer his planet before fellow H'lvenite Ch'p becomes a Green Lantern and defeats him.
When the multiverse is destroyed in Crisis on Infinite Earths, Ub'x survives by using his Sucker Stick to transform into pure energy. He reconciles with and befriends Ch'p due to the two being among the few beings who remember the original universe before relocating to Africa and creating a rodent-like species similar to the H'lvenites.