Yawgmoth, the Great Plague

Indestructible
{x}{1}{b}{b}: Put {x} -1/-1 counters on each creature
For each creature that dies with a -1/-1 counter on it put a counter on Yawgmoth, the Great Plague
If Yawgmoth, the Great Plague has 5 or more counters exile it and return it transformed to the battlefield under its owner's control.
has 5 or more counters exile it and return it transformed to the battlefield under its owner's control.