The Spotted Green Puffer has a stout rounded body shape with small spines. The face is very cute, having a smallish mouth topped by slightly bulging eyes and a broad forehead . Like many of the pufferfish, the coloring of the Spotted Green Puffer can vary. The adult is a beautiful rich green on top with dark spots and a whitish belly. In juveniles the green is less colorful.
Pufferfish have the ability to 'puff' themselves up with water or air if threatened. When they inflate, their spines protrude outward and this apparently helps keep them from being eaten. Another defense of many puffer species is to produce toxic substances in their flesh that is poisonous if eaten