What can I keep in this gosh damn stupid tank?

It is a 3 Gallon Marina tank. It was 30$, I cannot return it, and I cannot get a bigger tank. What can I do with the damn thing? What can I keep in it? I do not want Shrimp and I already have African Dwarf Frogs. I do not want just one fish, I'd like a community tank filled with small fish. I will consider a Betta if some other fish can go with it.