Uhm-Mav, Spawn of Silence

Enrage - Whenever Uhm-Mav, Spawn of Silence is dealt damage, target opponent sacrifices a creature.
{b}{b}{b}, Sacrifice a creature: Return Uhm-Mav, Spawn of Silence to the battlefield.
Every being that casts a shadow can be claimed by it. It will come and go like the breeze, carrying with it the souls of those once immortal.