These are for the most part regular zombies, however they pop up in movies all the time. In Romero’s Land of the Dead there is a scene where one of the survivors is found having offed himself and once cut down starts terrorizing everyone around him. Where these zombies are a bit less dangerous than many other types, they are still extremely dangerous. After all, you are probably looking low, checking for crawlers, and walkers but how often do you expect an attack from above? Not often!
That being said it’s pretty easy to underestimate how dangerous they are. Due to hanging they will likely be unable to grab or bite as effectively as they would if they got down.