Anubis, Bearer of the Scales

When Anubis attacks, all creatures your
opponents control that do not have a kill counter
gain a kill counter. (If a creature with a kill
counter kills or exiles another creature, increase the
kill counter by one.)
If a kill counter equals the creature's toughness,
tap the creature, it does not untap during its
controller's next untap step, and remove the kill
counters.