Crush-Depth Mage

Hexproof, Unblockable
Pickpocket 3 (Whenever this creature deals combat damage to a player, reveal the top card of that player's library. If it's a nonland card with converted mana cost 3 or less, you may cast it without paying that card's mana cost.)
From below the waves, she claims what she wishes. She steals spells to add to her collection, like baubles nestled amongst the coral.