Priestess of Jiangshi

Brood of Guaiwu - As long as you control a
Mutant creature, Mutant creatures you control
have haste.
Whenever a Mutant creature you control dies,
you may sacrifice a number of Mutant creatures
equal to the converted mana cost of that
creature. If you do, return that creature to the
battlefield with X +1/+1 counters on it, where
X is the number of creatures sacrificed this way.