Here is the full list of all 22 Fear The Wolves achievements.
Revive an injured teammate
Kill 3 enemies during a match
Kill 5 enemies during a match
Kill an enemy in melee
Kill 5 wolves during a match
Kill 3 enemies with headshots during a match
Kill your first enemy
Win your first battle
Win a battle by evacuation
Win 5 matches
Win 15 matches
Kill 20 enemies
Kill 50 enemies
Kill 5 enemies in melee
Kill 10 enemies in melee
Kill 50 wolves
Kill 100 wolves
Evacuate without killing anybody
Get a Wolf Matriarch heart
Use a Spore Artifact
Avenge your teammate’s death
Unlock all items of a single rewards set