def not a red terror. i was thinking stressed midas but he looks happy. looks very possible that he is a hibrid and you will probably never know for sure if that is the case. i hav a hybrid that looked almost identical to him when small, i'm pretty sure mine is a uropthalmus(cuban) trimac cross and i really like her now, shes a sassy one, tries to make babies with anything that swims by. keep that in mind as he grows.
other than that i have no better guesses. good luck!