Chtho, the eternal hunger

Trample
{b}{r}{g}, Sacrifice a creature: Choose one —
• Each player choose a creature he control, then it fights target creature he doesn't control.
• Each player may discard a card, then draw a
card and lose 3 life.
Whenever a creature is put into a graveyard from anywhere, Chtho gain +1/+1 until end of turn.