Flying Each creature you control is a Vampire in addition to its other creature types and has "Whenever this creature deals damage to a creature, put a +1/+1 counter on this creature."
Choose one — • Sacrifice any number of creatures. You gain 3 life for each sacrificed creature. • Pay X life, then look at the top X cards of your library. Put one of those cards into your hand and exile the rest. Entwine {B}
Relentless Rats gets +1/+1 for each other creature on the battlefield named Relentless Rats. A deck can have any number of cards named Relentless Rats.
As an additional cost to cast this spell, sacrifice any number of creatures. Target creature gets +2/+2 until end of turn for each creature sacrificed this way.
You may pay {W}{U}{B}{R}{G} rather than pay this spell's mana cost. Trample At the beginning of your upkeep, you may untap target creature and gain control of it until end of turn. That creature gains haste until end of turn.