Underworld Retriever

Escape—{b}{b}, Exile two or more other cards
from your graveyard. (You may cast this card from
your graveyard for its escape cost.)
You may cast creature spells from among cards
exiled with Underworld Retriever.
Whenever you cast a creature spell from your graveyard or from exile, put a +1/+1 counter on Underworld Retriever.