The scene where Professor Hamasaki infects Haruhi is a reference to the eyeball gag scene from Zombi 2.
Archive recordings of Allan Trautman as the voice of Tarman are used whenever a zombie yells "Brains!", "Live brains!", or "More! Brains!"
The older and younger teacher leading their students out of the school resemble James Karen and Thom Mathews, respectively; as such, they're called "Not-James Karen" and "Not-Thom Mathews", respectively, in the closing credits. They even say a few lines spoken by Karen and Mathews in the first two Return of the Living Dead films (e.g. "Watch your tongue, boy, if you like this job!"/"Like this job!?", "How do you kill something that's already dead?", "The brains! Right!", and "Look alive.").