A thought I had about Jerrys Friend/Assistant/Daytime Guardian Billy Cole

Monsters meeting and then hanging out and becoming friends due to their shared outcast status makes sense, and it also ties in with Jerry telling "Evil" Ed that he understands the pain of not fitting in before turning Ed.

I always thought Billy curdling upon his death was a sense of time finally catching up to his body. Decomposition was finally doing to Billy what it should have done ages ago.

Jerry calling to Amy for help and it not working, making him angrily slam his hands against the roof (alerting Charlie and Peter to his whereabouts) is another piece of evidence that leads me to think he shares some kind of supernatural connection with those he turns. Whether its magic or psychic, its supernatural and we are never told why he can do these things. He could have met Billy Cole and they really did become friends and allies. Or maybe he turned Billy but did something different that made Billy not fully become a vampire. Which is why its easier to call him a ghoul. But if my theory is correct, and you look up both the definitions of Ghoul and Zombie. Billy Cole actually fits the definition of a Zombie.

The second half of the first definition of Zombie is "a corpse that has been reanimated, especially by means of a supernatural power or spell". Billy Cole is walking and talking, sentient and alive, but what if he is just an animated corpse that time has not collected yet? It explains his automatic protective behavior of Jerry, and why he rots and curdles before going skeleton, only for the final shattering before dust? With the spell undone the corpse is no longer protected from decomposition.

In Fright Night Part 2, Brian Thompson plays Bozworth an Ally of Jerrys Sister, and he is seen commenting on various insects and their names before devouring them. By the third definition of Ghoul "One who delights in the revolting, morbid, or loathsome" fits his character perfectly!