Whaill, Monster of Plasma

Whenever a creature enters the battlefield, that player may pay {4}. If they don't, they must sacrifice a creature.

Whenever you sacrifice a permanent, exile target
card from a graveyard. If it was a creature card,
make a token copy of it under your control.

"I've seen it before, its warping wails entice people
and beasts alike to fall under its aid like peons to its cause."— Monster Handler Matt