Here is the full list of all 16 BEARZERKERS achievements.
Die 100 times
Die 1000 times
Complete every Gauntlet level
Complete a Gauntlet level
Complete a Gauntlet level alone
Complete a Gauntlet level without dying
Complete a Gauntlet level without using a respawn credit
Get killed by a falling meteor
Be under the effects of Oil Slick and Frost Nova at the same time
Get killed by a bear that is under the effects of Frost Nova
Get killed while under the effects of Shockwave
Get killed by a bear that is enraged by another player
Blink through a bear
Be under the effects of Oil Slick and Rocket Boost at the same time