Gravitum, the Gravity Cannon

Equipped Creature has "{p/g}{p/g}{p/g}{t}: Tap all
creatures with a Gravity counter. These creatures
do not untap."
Whenever equipped creature deals combat
damage to a creature, that creature gains a
Gravity counter.
Equip {2}
For each Legendary Artifact equipped to the
target creature, pay {1} more to equip this card