get a few eclips cats, they gwt about 14" bright yellow. they look pretty cool in schools of 4-6.
or get a channel. and when it gets fryin size, eat it, then get another one...lol
and video tape you fishin for it in the tank...lol
or a yellow or brown bullhead, the blacks arent that interesting, and my oscar tends to eat them as soon as i put them in, but leaaves the others alone. i dont know if oscars like blacks but you could try it. and blacks tend to grow slower and stay small.(under 10")