Ogopogo, Depth's Terror

Ward - Discard a card

When Ogopogo, Depth's Terror enters the battlefield, target player mills half of their library, rounded up. If Ogopogo, Depth's Terror is one of the milled cards, each opponent mills half of their library, rounded up instead.

Whenever a player mills one or more cards, put a +1/+1 counter on Ogopogo, Depth's Terror.