The painted frogfish grows up to 30 cm (12 in) long. Like other members of its family, it has a globulous, extensible body, with soft skin is covered with small dermal spinules. Its skin is covered partially with few, small, wart-like protuberances, some variably shaped, scab-like blotches and many small eye spots (ocelli) which look like sponges holes. Its large prognathous mouth allows it to consume prey its same size.
The coloring of the body is extremely variable because they always tend to match their living environments. Frogfishes have the capacity to change coloration and pigment pattern in few weeks. However, the dominant coloration goes from white to black, passing through a whole range of related nuances such as cream, pink, yellow, red, and brown, usually with circular eye spots darker than the background color and/or with saddles and blotches. Some specimens can easily be confused with Antennarius maculatus. These characteristics can help to separate the two close species: usually, A. maculatus has red or orange margins on all fins, and sometimes a spike of the saddle blotch starts posterior to the eye, numerous warts on the skin, andfew or no ocellis; A. pictus has also three eye spots on its caudal fin. Juveniles can have a dark background color with small yellow spots.