The One Ring

Indestructible
Equipped creature gets +3/+3 and can't be blocked except by Ringbearers.
At the beginning of your upkeep, put a -1/-1 counter on equipped creature. When equipped creature dies, flip a coin. If you win the flip, you may equip the One Ring to target creature. If you lose the flip, put the One Ring at the bottom of your library.
Equip {2}