The South American Puffer Fish, also known as Colomesus asellus, is a freshwater fish native to South America. It is a small fish that can reach up to 3 inches in length and has a distinctive, round body shape. Puffer Fish are known for their ability to inflate their body when threatened, making them appear larger and more intimidating to predators. They are also known for their toxin, which can be deadly if ingested. Puffer Fish are popular in the aquarium trade but require specific care to thrive.