Here is the full list of all 21 Zombie Gotchi achievements.
Happy Happy Happy!
Looks like your Brain next!
Did i meant "Alive"?
Snack Bubble!
Coming Home!
Best Hair Ever!
Yummy, Bunny!
Did you hit?
Do you remember?
Delicious!
Didn't liked your Zombie?
It will survive you!
Still no sign of life!
There is something in there!
They looking friendly!
Yay, Zombies get ill?
You have gotten a Boy!
Let's battle!
I can see living People!
You survived the Tutorial!
You have gotten a Girl!