The masked puffer (Arothron diadematus) is a pufferfish in the family Tetraodontidae.

Maximum length 30 cm, olive-green/grey with a black mask over the eyes and pectoral fins, mouth has a black border.

[2] Usually solitary but schools during mating period.

Some authors believe this to be a variation of the species Arothron nigropunctatus.

[3] Associated with coral reefs, from surface to 20m depth.