Charybdis, Scourge of Sailors

Charybdis cannot be the target of Enchant Creature spells.
When Charybdis enters the battlefield, return up to four target creatures to their owner's hands.
{x}{x}{u}{u}{t}: Tap X creatures where X is the mana spent, they do not untap during their controller's next untap step. Do this only during your pre-combat main phase.