Thenae, Harbinger of Thassa

Whenever a card is put into an opponent's
graveyard from their library, exile that card.
At the beginning of your upkeep, you may put a
creature spell that was exiled by Thenae onto the
battlefield under your control, except it's a
Crab in addition to its other creature types.
{1}{u}{b}, {t}: Each opponent mills three cards.
_________________________________________
She tells her father's lies.