John Schoenherr's cover perfectly captures the nature of the beast-team and mood of the book. I think there is no better-looking edition to be found.

The Beast Master - I read my copy decades ago and have forgotten most details, so for a decent plot summary, I once again rely on P. Schuyler Miller, and quote part of his review in Astounding (March 1960):

"Storm is a Navajo Indian, one of the last survivors of a planet that was destroyed in a war with the humanoid Xiks. With the animals he has trained, and with whom he is in rapport, he joins the explorers and settlers of the colonial world, Arzor. Because, on Arzor, he expects to find the enemy he has never seen and whom he must kill for the honor of his tribe and his people.

Needless to say, much happens before young Storm, his eagle, his sand cat and his two meerkats, come to grips with that hereditary foeman. He finds Arzor with its wild-horse herds much like the plains of lost Terra, and its goat-horned tribesmen good friends. He uncovers a triple mystery - of human outlaws who masquerade as natives, of a hidden outpost of the Xiks, and of an unknown, ancient race from beyond the stars, whose secrets are buried in the honeycomb of tunnels under Arzor's wild Peak country. And he finds his own Indian heritage both a handicap and an advantage in dealing with the native Norbies, whose ways are so like those of the ancient Navajos in the days before Man took to Space." [P. Schuyler Miller]