Greatwurm Predation

Delve (Each card you exile from your graveyard
while casting this spell pays for {1}.)
Create a 6/6 green Wurm creature token with
trample. If you spent eight or more mana to cast
this spell, that creature gets +6/+6 until end of
turn and fights up to one target creature you
don't control.
It starts with small prey before gorging itself on
whatever it pleases.