The video shows a catfish and a puffer fish in an aquarium. The catfish is gray and has long barbels, while the puffer fish is yellow with black stripes and has a round body. The catfish is seen swimming around the puffer fish, which is lying on the sandy bottom of the tank. The catfish approaches the puffer fish from behind and appears to nudge it with its body. The puffer fish does not seem to be bothered by the catfish's actions and remains stationary throughout the video.