A fossa is a slender, long-tailed, cat-like mammal that is endemic to Madagascar). It is the largest mammalian carnivore on Madagascar and has been compared to a small cougar, as it has a similar appearance, but with a slender body and muscular limbs, and a tail nearly as long as the rest of the body). Here are some key facts about fossas:

• Classification: The classification of the fossa has been controversial due to its shared physical traits with viverrids, mongooses, and Felidae. Its compact braincase, large eye sockets, retractable claws, and specialized carnivorous dentition have led some taxonomists to associate it with the felids. In 1939, William King Gregory and Milo Hellman placed the fossa in its own subfamily within Felidae, the Cryptoproctinae).

• Appearance: The fossa appears as a diminutive form of a large felid, such as a cougar, but with a mongoose-like head, relatively longer than that of a cat, although with a muzzle that is broad and short, and with large but rounded ears. It has medium brown eyes set relatively wide apart with pupils that contract to slits. Its coat is reddish-brown, and its muzzle resembles that of a dog. It has retractable claws and fearsome cat-like teeth).

• Habitat and Behavior: Fossas are unique to the forests of Madagascar, an African island in the Indian Ocean. They are the largest carnivore and top predator native to Madagascar and are known to feed on lemurs and most other creatures it can get its claws on, from wild pigs to mice. They are expert climbers and spend their time both in the trees and on the ground. They are active at night and also during the day. Females give birth to an annual litter of two to four young, and adulthood is reached after about three years. Fossas are generally solitary, except for the breeding season. Males and females will occupy territories defined by scent marking. Females will mew to attract males, and the males will howl and yowl while competing for the female.

• Conservation Status: The fossa is listed as "Vulnerable" on the IUCN Red List, and its current population trend is decreasing. Habitat loss and fragmentation, hunting, and competition with domestic dogs are the main threats to the species.

It is important to note that "FOSSA" can also refer to an open-source management platform.