The Green puffer fish doesnt exceeds a lenght of 17 cm. He has the typical heavy-handed form of all puffers. Head and trunk are covered with tiny, dense spines, which may also be absent in rare cases and stand up upon inflation. In coloring and drawing, he is quite variable. The back and sides are yellow-green to emerald-green and densely covered with large, brown to black, round spots. They are often brightly edged and can fuse on the back Beamlike structures. The belly is white, gray or yellowish in older fish and only occasionally spotted. There are two forked short tentacles on the nostrils. The Green puffer fish is easily confused with Tetraodon fluviatilis and has been described in older Aquarsistikfachbüchern under this name. A reliable distinguishing feature is the eye color, which is yellow and red with Tetraodon fluviatilis in Tetraodon nigroviridis.