Star Wolf

Starwolf is a series of three novels by Edmond Hamilton featuring heavy-worlder Morgan Chane. Chane was the son of a human missionary family to a heavier-than-Earth-normal world (higher gravity) of Viking-like aliens. His parents died and left him an orphan to be incorporated into the Starwolf society. As an adult he felt himself to be as much a Starwolf as his alien companions. After a dispute over plunder with a fellow Starwolf (leaving the other Starwolf dead), Chane flees (under threat of death) from Starwolf society. As a fugitive and hiding his ex-Starwolf status (the rest of the galaxy "declares a holiday when a Starwolf is killed"), Chane becomes part of a "Merc" human mercenary group commanded by a Merc named John Dilullo.