Nightmare Fuel: The closest things we get to scares are the fact we don't see what the lizard DOES to its victims (bit of a letdown, but judging by the screams in the train, it wasn't pretty) and the trailer. Said trailer makes good use of its music and signature line: "You're driving a lonely road...You're as good as dead...".
Special Effects Failure: The props occupying the sets that the lizard (which was a real Gila monster) crawls on are pretty obviously miniature models. It also turns out it's not even a real Gila Monster, but a Mexican Beaded Lizard. They couldn't even get the species right.