My 6 inch Red Oscar does the same thing. I've had him since he was 1 inch long, along with 2 Tiger Oscar's the same size; purchased at the same time. My Red Oscar has been having night terrors almost every night since I brought him home. I originally had 4 Oscars two Red and two Tiger. One of the Reds died after 2 months. They are currently in a aggressive community grow out 55 gal. I have had and have all kinds of big aggressive cichlids in several tanks. But this 1 little Red Oscar has been having at least one crazy nightmare all most every single night. It is the weirdest thing, no other fish that I have had has ever done anything like this. I've been taking care of freshwater fish since age 5; I'm 42 and have never seen a fish have a possessed nightmare every single night. Unfortunately, I will be selling him before he destroys my aquarium. I will definitely tell my local fish store or who ever buy's him about this as a full disclaimer. He's such a beautiful Red Oscar, full of all kinds of personality. He may get euthanized in the end though, because he'll need a huge forever home. Bigger then my 6ft 125gal, because the bigger he gets the more dangerous those night terrors are going to become. I have two Tiger Oscar's 10 inches+, plus several other aggressive cichlids the same size in two 125gal aquariums. He would scare the bejesus out of all of them at night if I put him in 1 of those tanks!!!