The Deathworld Omnibus by Harry Harrison
The first planet was called Pyrrus ...a strange place where all the beasts, plants and natural elements were designed for one specific purpose: to destroy man. The second planet was unknown ...a savagely primitive place where every man had to kill other men - or live as a slave. The third planet was called Felicity ...a joke, but not for those compelled to live there, along with the creatures bred for thousands of years for a single, deadly purpose. And one man, Jason dinAlt, has to face all three.