Schmendrick, the Magician

Magic, do as you will - Whenever Schmendrick
becomes tapped, choose target creature you control.
That creature loses all abilities. Roll a d20.

— 1 -10: That creature becomes a 3/5 Unicorn
with Defender.
— 10 -19: That creature becomes a 4/6 Unicorn with Lifelink.
— 20: That creature becomes a 7/7 Nightmare Ox
with Menace and Annihilator 1.