Draksar, Skeletal Lich

Pile of Bones - Whenever a creature dies, create
X Bone artifact tokens where X equals that creatures toughness.

{b/g}, Sacrifice 1 Bone token: Create a 1/1 black
Skeleton creature token with deathtouch.
{1}{b/r}, Sacrifice 2 Bone tokens: Create a 4/1 black
Skeleton creature token with Menace.

Sacrifice a Skeleton: Regenerate this creature.