Things that bother me in NIGHTBREED...
Why is it that when Boone gets bitten, there's a circular white special effect appliance under his bloody t-shirt? I'm referring to when he's bitten by "the Beast" after he first visits Midian, the bloody bite mark has white rubber or something under the prosthetic bite -- then, later, when he's stabbed, his injury has what appears to be a white card of some sort around it, and when Boone later pulls the knife out, he looks down on the card, and noticeably pulls it off -- I almost wondered if it was a weird mutant Nightbreed power that made these things appear, since he looked at it, but I've never seen this in any other movie.
Another thing that bugs me about the movie is the gum-chewing dude who rips his face off -- his 1950s Auto Mechanic performance is annoying and inappropriate, and why do certain peripheral characters have to throw out one-liners like, "There goes the neighborhood..."? If they didn't talk at all, they'd appear more menacing. Otherwise, I like this movie. There's very little I'd modify.