Chanrix, the Lurker

Whenever Chanrix, the Lurker or another crab
enters the battlefield under your control each opponent mills four cards.
Landfall—Whenever a land enters the battlefield
under your control, you may exile a card from
target opponents graveyard. If a card with mana
value three or less was exiled this way scry 1. If a
card with mana value four or greater was exiled
this way you may have that player mill a card.