The Fossas were one of the main villains in Madagascar; they were seen in Madagascar as the main antagonists, and in Madagascar: The Video Game as supporting villains. They appear as medium-sized weasel-like creatures and rarely speak, instead usually growling and yelping.

Throughout Madagascar, they are shown to terrorize the lemurs and attempt to eat them. According to Julien, "they're always annoying us by trespassing, interrupting our parties, and ripping our limbs off." When they do speak, they put "fossa" in front of every word: ex. "Fossa hungry, fossa eat." They are terrified of Alex due to him being a lion and being much more physically powerful and intimidating. In the end, thanks to a setup performed by his friends and the penguins, Alex made sure that the fossas never bothered the lemurs ever again.

They were voiced by Tom McGrath.

Madagascar
Media Films Madagascar • Madagascar: Escape 2 Africa • Madagascar 3 Short films The Madagascar Penguins in a Christmas Caper • Merry Madagascar TV series The Penguins of Madagascar
Characters Main Characters Alex • Marty • Melman • Gloria • King Julien XIII • Maurice • Mort Penguins Skipper • Private • Kowalski • Rico Other characters Lemurs • Mason and Phil • Ted Florrie • Zuba • Moto Moto • Marlene Villains Fossas • Nana • Makunga • Teetsi • Mr. Chew
Music Soundtracks Madagascar Soundtrack • Madagascar: Escape 2 Africa Soundtrack Songs Best Friends • I Like To Move It • Hawaii Five-O • Boogie Wonderland • Whacked Out Conspiracy • Chariots of Fire • Stayin' Alive • Zoosters Breakout • Born Free • The Fossa Attack • Beacon of Liberty • What a Wonderful World Once Upon A Time In Africa • The Traveling Song • Party, Party, Party • I Like To Move It • The Good, The Bad And The Ugly • Big And Chunky • Chums • New York, New York • Volcano • Rescue Me • More Than A Feeling • She Loves Me • Foofie • Copacabana (At the Copa) • Monochromatic Friends • Best Friends • Alex On The Spot