Here is the full list of all 49 Animalistic achievements.
Begin the process of constructing the vaccine
Collect the Vial
Beat a level without killing an enemy.
Beat the game.
Defeat Animalistic's final boss
Listen to 5 audio logs
Solve one torch puzzle
Punch an exploding barrel into an enemy.
Complete 15 levels
Kill Thor the Boar.
Kill 50 flying animals.
Complete 10 levels.
Kill Carl the Croc.
Solve one flying bat puzzle
Beat a level without taking any damage.
Kill 1,000 animals.
Kill 6 enemies at once while Animalistic.
Spend 30 minutes in one level.
Solve one password puzzle
Read 5 notes
Receive every death message.
Die 10 times in one level.
Find the first anonymous note
Beat a level only using fists.
Punch through 100 doors.
Go Animalistic!
Kill a shield enemy with only your fists.
Kill one of each animal species.
Destroy 5 collectables.
Kill an enemy with your slide.
Kill 2 enemies with one shotgun blast.
Complete 5 levels.
Get shot 20 times in a level and beat it.
Kill an enemy with every gun.
Kill an enemy by throwing your gun at them.
Kill 10 enemies with one assault rifle.
Kill 100 animals.
Use a bomber to kill another animal.
Complete a level in one minute.
Die for the first time.
Destroy all collectables.
Kill 5 enemies with one exploding barrel.
Beat a level using every type of gun in the game.
Complete a level with less than 10% of your health remaining.
Complete all levels without dying.
Beat all levels using only your fists.
Beat the game in under 45 minutes.
Collect the Walkie Talkie
Collect the Biosample Gun