No way is that an oscar if its in a tank with tetras. Oscars are Big.
Maybe a Molly? Dalmation mollies come in various patterns. I just can't see the fins outline, which is really the only way to discern most fish.
I finally figuered out what he is! Opaline Gourami (Trichogaster trichopterus). It is the only thing I have found that can even match him. Its only taken me all day and a ton of internet searching.....