O.K. Quack has a spaceship which he can shrink down to the size of a coin.
Coincidentally, many of his stories is about him trying to find the spaceship, which often gets mixed up with regular coins.
He has vast telekinetic powers, able to lift entire buildings when concentrating. The effort leaves him exhausted and stuttering. He comes from a pacifistic civilization and is surprised at the greed and conflicts common on Earth.