In the video, a puffer fish is seen swimming in a tank. The fish has a yellow and black body, with a white belly and a long, pointed nose. Its eyes are large and round, and it has a small mouth. The fish moves slowly and gracefully through the water, occasionally turning its body to show different angles. The background of the tank is a dark, murky color, with some rocks and plants visible. There are no other fish or objects in the tank with the puffer fish.