Oscars are thought to be one of the most intelligent aquarium fish available, and are one of the few species that can be trained to do tricks.
Oscars however are not a community fish, they should be kept in a species only tank, and they can grow very large, very quickly.
They require a lot more maintenance than other fish, due to their carnivorous nature and the amount of waste they create.
On the positive side, they are one of the few species you can hand feed; they will often eat food from between your fingers. Oscars thrive when kept in pairs, or group of 5+, and should be housed together from a young age.