Massive lore shit in the previous chapter and now too,because it seems to be like peeking a look into ghost ecosystems and hierarchy,and how intelligent/deranged they are.
If an ghost has multiple heads,it seems to have vague and more sinister intentions,while single headed ghosts have more intelligence and a more precise goal.
It also helps that if it retains its shape from when it was alive,it is also more sane and intelligent.
An example would be the ghost from before,the ghost that was following the playboy,and the fat guy with a noose thing.
Those didn't do much harm,and didn't seem to want to hurt their victims.
For the more deranged and sinister ones,we have the groper ghost that had a lot of arms,and the ghost that had a head on its crotch.
It seems that the more simplistic ghosts are very small with an instinctual desire for life energy.
It seems that emotions should also play a part in how the ghost is shaped,from the chapter with the cat,seeing as the seemingly nice guy has a grouping of seemingly crying dogs and cats surrounding him,all of which are deformed in one way or another,while the Bald guy's ghost following was very clean looking,and have a peaceful expression.
TL;DR:
The ghosts are shaped by their past emotions.
The ghosts are more sane and intelligent the more humanoid they are,and are more deranged and sinister the more deformed they are.
Some ghosts are deformed just because of past incidents,while others are deformed out of their desires.