Here is the full list of all 14 Necro Rumble achievements.
You've just began your odyssey as a Necromancer.
No one is standing anymore.
Brave of Warrior
Freindship of Archer
Love of Ghost
CawCaw
CawCawCawCaw
CawCawCawCawCawFlapCawCawFlapCawFlap
Taking candy from a baby
One shot, One kill
The scream of mortals echoes through the air.
All three of them grew up strong!
Unkillable Necromancer King
All My Family