Thats a channel cat, and its going to get way bigger than your tank can hold! I would rehome it as quickly as possible, then you will have the following options:
1. Keep the goldfish (if its a fancy, the comet and common goldfish will get cramped in that tank) and maybe get one or two more fancies. Get rid of everything else except the snails.
2. Keep the barbs (if they're not tiger barbs, they can get nippy), red tail shark, gourami, and ottos. Get rid of everything else except the snails.
3. Keep the angels, red tail shark, and barbs (if they're not tiger barbs, they'll tear up the angel's fins). Get rid of everything else except the snails (don't keep the ottos since when the angel gets big enough, they will eat them). Also, if you happened to get a male and a female angel and they paired up, its fine to keep them together. If you got two females or two males or they won't pair up, you might run into aggression issues.
4. Keep the clawed frogs, maybe the red tail shark, maybe the barbs, and the snail. Get rid of everything else.
Also, in the choices where you can keep the oto, I would get some more otos (2 or 3), since they enjoy company.