Wendigo

At first the creature looks like an emaciated man running, then it looks like a large wolf. Right before it attacks, it is obvious the creature is neither.

Born of Greed and Starvation. The wendigo’s origins are mysterious. Some claim they are beings summoned forth from the corpses of humans who have died of starvation. Others say they come from those who have died because of cannibalism or their own greed.

An Insatiable Appetite. Wendigos are found in harsh climates, preying on the weak and hungry. Legends speak of entire settlements devoured by a single wendigo. All that remains of these settlements are eerily silent buildings and a few scattered bones, all material wealth untouched.

An Emaciated Horror. Wendigos have an emaciated humanoid shape with some disturbing lupine features, described by one scholar as a “hairless zombie werewolf.”

Punisher of Vices. Wendigos also have a special role in the punishment for cannibalism and greed. Greedy or cannibalistic individuals whose vices have caused the deaths of others, directly or indirectly, might be cursed by those victims as the victims die. This curse manifests as a wendigo being unleashed into the world.

Wendigo's Frozen Heart. As part of the curse that creates a wendigo, the heart is shriveled and covered in frost.

As long as its shriveled heart remains intact, a wendigo can’t be permanently destroyed, as it will continuously regenerate. The creature's ability to regenerate can only be stopped if its frozen heart is melted. A wendigo knows this and will often try to avoid places with a lot of fire. If a wendigo and its heart are separated, it will do everything in its power to get it back into its chest.

The wendigo’s heart has AC 5, 25 hit points, and immunity to all damage except fire.