Reflective Crab

Whenever one of more cards are put into your graveyard, target opponent mills that many cards.
Whenever Reflective Crab becomes the target of
a spell, you may copy that spell. You may choose
a new target for that spell and you may cast it
without paying it's cost.
Apprentices at Tolarian quickly learned that its
mirrored-shielding can cause serious headaches.