When not colonising a host, the Matango resemble large mushrooms, with unusually large spores emanating from them. The Larger mushrooms have nodular caps. After infecting a human host, the host will gradually grow mats of fungus over their skin, and gradually go insane. Once the Matango has matured, the Human's upper body is replaced by a fungal cap, and their lower body becomes equally deformed, with giant limbs and long claws.
The Matango are an unusual and undiscovered species of Mushroom which inhabit their own island in the South Pacific Ocean. After a ship, which had been damaged in a storm, landed on the island, its crew tried to search for food, and came across a natural marvel. Pools of water had been seemingly carved out of the ground, and were filled with rainwater, and an endless supply of the mysterious mushrooms. The crew went searching for other food, but found none except the mushrooms. Fearing the effects of eating something which they didn't know whether it was harmful or not, the crew resisted the urge to eat them. Strangely, they also discovered that another boat had previously arrived on the island, yet it was covered in mold which they tried to clean away using bleach.
Eventually, hunger set in, and one of the crew, desperate, ate some of the mushrooms. At first, they seemed to be perfectly fine, but over time, the mushrooms began to colonize their body in a way that was similar to the Cordyceps fungus. In addition, the infected crew member convinced more of his friends to eat the mushrooms, though this was probably a result of the Matango's own abilities. Eventually, all but one of the of the crew, Kenji, became infected by the Matango, and were reduced to the point of lumbering, insane, walking mushrooms.
Kenji escapes on the intact boat, and travels to Tokyo. At the end of the film it is revealed that he too is infected by the Matango, and is slowly beginning to transform, noting that the Humans and the Matango are very much alike.
In the Godzilla: Monster of Monsters, the Matango appear in their own hyperspace level sections in which the player, controlling Godzilla or Mothra, must destroy or evade a large Matango hive (coming in three different levels of difficulty) in order to clear the level. While trying to destroy the hive the player must also contend with projectile spores and even smaller individual floating Matango. Matango Hives can also appear shortly before the player fights one of the game's bosses, and attacking the Matango spawned from the hive rewards the player with health power-ups.
Initially, a Matango's host sounds and speaks like any human. After the Matango begins to fully colonize the person, their sounds are reduced to grunts and deep voiced laughter.