Meraph, Dimir Daughter

Skulk
{t}, Create a 1/2 black assassin token with deathtouch.
Whenever a creature you control with power 3 or less does combat damage to a player exile the top card of their library. You can play that card until end of turn and you may spend mana as though it were mana of any color to play it.
"You think your secrets are safe."
-Meraph, Dimir Daughter