Not to be confused with the first game's version, Bighorn Bison.
The Bighorn Bison is a returning enemy in Risk of Rain 2.
The Bison first starts appearing in the third level, Rallypoint Delta. They have no spawn animation, instead they just appear, and can attack as soon as they do so. Their signature attack is a ramming charge, an attack that can stun them if they hit a wall. They also attempt to gore the player with their horns in melee-range.
While the charge-attack can be dodged, the Bison will course-correct if it still has time.
Since they can't jump and have no ranged attacks, hopping on one of the boulders littering the tundra prevents them from reaching the player.