Ghouls
From Super-wiki
Ghoul
Where does the word ghouls come from? Before it came to be applied to any random sicko or serial killer it meant went all the way back to the medieval Arabic ghul...it will dig up graves to eat the dead.
– Alex Irvine, The Supernatural Book of Monsters, Spirits, Demons and Ghouls
In 4.19 Jump The Shark, the offspring of a ghoul killed by John Winchester lure Sam and Dean to their town in order to take revenge. They can shapeshift (by taking the form of the last person they "jumped down", and one takes on the form of Adam Milligan. Dean kills them by beheadng.
In some lore they are not dissimilar to zombies. They are corpses reanimated by witches or demons that can be commanded.