Here is the full list of all 35 Hybrid Animals achievements.
Reach level 6.
Chop someone's head off with a bladed weapon.
Breed a creature with a speed greater than 30.
Reach level 3.
Win a game of Natural Selection.
Shrink a player with the shrink ray, and squash him.
Breed two hybrids, resulting in a mutant made up of 4 animals.
Achieve a triple kill by crushing players as a giant.
Blow yourself up with the firecracker perk, and take out two other players in the process.
Use a creature in Deathmatch that you designed in the editor.
Collect 230 coins on "Vertical Madness"
Complete the level "Unstable Earth" without dying.
Collect 130 coins on "Parkour in Hell"
Headshot a player from over 30 feet with the guass shotgun
Headshot a player who is camouflaged.
Kill a player who is pulling you into his black hole, before the black hole kills you.
Achieve a triple kill by running into players while inside a Death-Ball.
Kill 4 players within 4 seconds of each other.
Kill 5 players within 4 seconds of each other.
Breed a creature with a damage greater than 30.
Breed a creature with an Health attribute greater than 30.
Breed a creature with all attributes greater than 24.
Breed a creature with all attributes greater than 30.
Win a game using a creature whose attributes are all less than 6.
Reach level 10.
Survive for a minute after being shot by the polarizor and having your gravity reversed.
Win a game of Bad Apple.
Kill all the non-infected by yourself, in Zombie Mode.
Complete all Challanges on Drunk Mode
Collect 60 coins on "Parkour in Hell" in Nightmare mode
Collect 60 coins on "Vertical Madness" in Nightmare mode
Complete "Unstable Earth" on Nightmare mode
Reach level 15.
Reach level 20.
Kill 3 players within 4 seconds of each other.