Barrowghast

Barrowghast
A hill giant who dies with an empty stomach, full of rage and regret, might become suffused with energy from the Negative Plane and rise as a barrowghast. Though it looks like little more than an animated corpse, a barrowghast is filled with necrotic energy and driven by spite and malice. Its blood is a thick and toxic ichor that gives the barrowghast a noxious stench.
Barrowghasts no longer hunger for physical food and instead crave life energy drained from living creatures. They often target former family members and allies, but they feast indiscriminately on any creatures they encounter. When barrowghasts drain Humanoids' life energy, those Humanoids rise as zombies.