Empire Star (1965)

ON THE INFINITY ROUTE
Comet Jo had a body that was brown and slim and looked like a cat's, and on his left hand were sharp brass claws with which he had already killed three wild kepards and a boy his own age. He also had a propensity for wandering, and this was to lead him on an adventure spanning uncounted light-years of space and incalculable spans of time, to free a race of beings upon whom the civilizations of the stars depended.

Along the way he would meet: the strange multiplex consciousness called Jewel; the beautiful, soul-burdened space traveler San Severin; a creature known as the Lump, who was half-alien, half-machine; Ni Ty Lee, the suicidal poet of the stars, who lived everyone's life but his own; a young princess of the Galactic Empire, fresh from Miss Perrypicker's Finishing Academy for Young Ladies ...

And finally he would meet - himself. A thousand times, or perhaps more.