Mortigan, Lord of Necropolis

{x}{1}{b},{t}: Create an X/X black Zombie creature
token.
{x}{1}{r},{t}: Create X Blood tokens, where X is
the amount of tokens you control.
{x}{1}{g},{t}: Sacrifice another creature you control
with power or toughness equal to X. Create that
many green 1/1 Insect creature tokens.