Mani, the Freezing Moon

At the beginning of your upkeep, draw a card,
then if you didn't take damage since your last
turn, transform Mani, the Freezing moon.
players can't attack you or planeswalkers you
control unless they pay {2} for each attacking
creature.
If Mani, the Freezing moon dies, exile it
instead, then at the beginning of your next
upkeep return it to the battlefield under your
control.