Book Wurm

This creature gets +X/+X where X is the
number of instants and sorceries in your
graveyard.
When this creature dies, you may cast an instant
or sorcery from your graveyard as though it had
flash. (You may spend mana of any type to do this.
If a spell cast from your graveyard this way would be
put into your graveyard, exile it instead.)