The Amazon Puffer, known scientifically as Colomesus asellus, is a small, freshwater puffer fish found in basins in tropical South America. While primarily a freshwater fish, the Amazon Puffer with live in slightly brackish, a mix of salt and fresh, waters, as well. The Amazon Puffer is also known as a Peruvian Puffer and is a popular aquarium fish. If being kept in an aquarium, the Amazon Puffer does better with company, although it will nip the fins of slower moving fish. The teeth of the Amazon Puffer grow very quickly and it is beneficial to feed them crunchy snacks.

Like other pufferfish, the Amazon Puffer inflates itself when threatened. It is migratory and non-territorial. This fish is easy to identify. Its body is green above and white below. Besides, it has a thicker black band across the dorsal surface of the body. This black band separates it from other similar-looking species it co-exists with and also makes it much sought after in the aquarium trade.