Nautilus, Titan of the Depths

Islandwalk, Trample, Protection from Instants
and Sorceries
At the beginning of combat on your turn, you
may attach an equipment to Nautilus.
When Nautilus attacks, you may unequip an
equipment attached to it. If you do, Nautilus
deals damage to target creature equal to the
mana cost of the unequipped equipment.