Poul Anderson is one of the most revered and influential of all science fiction writers and perhaps his greatest work is a novella, “Call Me Joe”. It just so happens that the subject of this work is a hybrid centaur.
“Call Me Joe” was first published in the science fiction digest, Astounding Science Fiction, in April 1957 with illustrations by the great fantasy illustrator, Frank Kelly Freas.
Later, the work was published in various story collections and is the featured work from “The Collected Works of Poul Anderson, Volume 1: Call Me Joe”, which features this cover art which is obviously a variation on the earlier cover art by Mr. Freas.
The character Elfangor (see below) from the series, Animorphs, is indebted to Anderson’s Joe as, may well be, James Cameron’s “Avatar”.