Dimir Sleeper

Lifelink, Fear(This creature can't be blocked except
by artifact creatures and/or black creatures.)
Transmute {1}{u}{b}(Discard this card: Search your library for a card with the same mana value
as this card, reveal it, put it into your hand,
then shuffle. Transmute only as a sorcery.)
When you transmute this card, target creature
loses all abilities and becomes a 3/3 Beast,Horror
with Lifelink and Fear until end of turn.