The Fossa: the Predator That Isn’t a Cat

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By Jordan Lamont · Last updated 7 October 2026

Say it like a local: fosa (FOO-sa) — and no, it is not a cat, however much it looks like one.

Madagascar’s top predator looks like a cat, climbs like a monkey, and is related to neither. The fossa is one of evolution’s great impersonators — a creature so unlike anything else that early naturalists struggled to classify it. If you want a single animal that captures how strangely life has evolved on this island, forget the lemurs for a moment and meet the thing that hunts them. (For where and how to see one, see our complete fossa guide; this is the story of what it actually is.)

The cat that is not a cat

Everything about the fossa (Cryptoprocta ferox) says “cat”: the lithe body, the retractable claws, the fearsome teeth, the stalking gait. But it is not a feline at all. The fossa is the largest living member of the Eupleridae — a carnivore family unique to Madagascar — and its closest relatives are mongooses. Its cat-like form is a case of convergent evolution: isolated on the island with no true cats, a mongoose-relative simply evolved to fill the big-predator niche, growing into something that looks uncannily feline without being a cat at all.

Apex predator of the eighth continent

At up to 1.8 metres from nose to tail-tip and around 12 kilograms, the fossa is the largest carnivore native to Madagascar and sits at the top of its food chain. Its main prey is lemurs, which it pursues with astonishing agility through the trees — using its long tail for balance — as well as on the ground, taking everything from wild pigs to mice. It kills with a bite to the skull. On an island with no leopards or big cats, the fossa is the shadow every lemur fears.

Strange even for Madagascar

The fossa’s oddities go deeper than its looks. It is active by day or night depending on its prey, and usually hunts alone. Most curiously, it is one of only a handful of mammals in which young females go through a temporary phase of “masculinisation” before maturity — a biological quirk still not fully understood. Even among Madagascar’s catalogue of evolutionary one-offs, the fossa stands out.

Why it matters today

The fossa is the keystone of Madagascar’s forests — and, like the lemurs it hunts, it is threatened by their loss. Seeing one is a rare privilege. Read our full guide to finding the fossa, and plan your wildlife trip with our Madagascar travel guide.

FAQ

Is the fossa a cat?

No. Despite its cat-like look, the fossa (Cryptoprocta ferox) is the largest member of the Eupleridae — Madagascar’s own carnivore family, related to mongooses.

How big is it?

Up to about 1.8 m (6 ft) nose to tail and around 12 kg — Madagascar’s largest carnivore and apex predator.

What does it eat?

Almost anything it can catch, but above all lemurs; it hunts expertly in the trees as well as on the ground.

Where can you see one?

They are elusive; the dry forest of Kirindy near Morondava is the most reliable place. See our full fossa guide for details.