Gozmol

Gozmol, Brutish Bogan Hunter is a unique Bogan Brute that can spawn in Paths of the Drowned in Diablo III. He is a very rare spawn, and has not been reported to appear in Adventure Mode. It is possible that such spawning rate was a bug, but it has been increased in patch 2.2.0.

Killing him was originally required for the Irreplaceable You achievement.