lion, (Panthera leo), large, powerfully built cat (family Felidae) that is second in size only to the tiger; it is a famous apex predator (meaning without a natural predator or enemy). The proverbial “king of beasts,” the lion has been one of the best-known wild animals since earliest times. Lions are most active at night and live in a variety of habitats but prefer grassland, savanna, dense scrub, and open woodland. Historically, they ranged across much of Europe, Asia, and Africa, but now they are found mainly in parts of Africa south of the Sahara. An isolated population of about between 500 and 700 wild Asiatic lions constitute a slightly smaller population that lives under strict protection in India’s Gir National Park and Wildlife Sanctuary.

The lion is a well-muscled cat with a long body, large head, and short legs. Size and appearance vary considerably between the sexes. The male’s outstanding characteristic is his mane, which varies between different individuals and populations. It may be entirely lacking; it may fringe the face; or it may be full and shaggy, covering the back of the head, neck, and shoulders and continuing onto the throat and chest to join a fringe along the belly. In some lions the mane and fringe are very dark, almost black, giving the cat a majestic appearance. Manes make males look larger and may serve to intimidate rivals or impress prospective mates. A full-grown male is about 1.8–2.1 metres (6–7 feet) long, excluding the 1-metre tail; he stands about 1.2 metres high at the shoulder and weighs 170–230 kg (370–500 pounds). The female, or lioness, is smaller, with a body length of 1.5 metres, a shoulder height of 0.9–1.1 metres, and a weight of 120–180 kg. The lion’s coat is short and varies in colour from buff yellow, orange-brown, or silvery gray to dark brown, with a tuft on the tail tip that is usually darker than the rest of the coat.

I’ll save the biggest enemy to last.
Packs of hyenas can cause lions problems and gaur buffalo have been known to kill lions also. Gaur are particularly powerful adversaries with superb weaponry and will kill lions on sight to protect their young if they get the chance.

For male lions with a pride one of the biggest enemies is other male lions trying to take over. A male lion will defend his pride to the death which is why lions have a maximum of around 3 years in charge. This is actually a good thing as it lessens the chances of incest.

No, the relationship between lions and cheetahs is very firmly in favour of the lion. If there’s a rivalry it’s very one-sided.

The reverse might be true, and the cheetah’s “biggest enemy” could well be a lion. Lions kill cheetah cubs, as well as adults when they can catch them. They’ll also easily steal cheetah kills. There’s no way a cheetah could stand up to a grown lion.

Cheetahs are the whipping boys of the savannah, basically. They sacrifice some size and strength for their rapid speed, so once they’ve caught their prey, many other predators can bully them off their kills. Eating a meal is an exercise in paranoia, because they know it’s only a matter of time before something bigger and “badder” comes along.

They’re very successful hunters compared to lions, but that doesn’t matter, because scavenging is much easier and less energy-intensive. (And lions scavenge a lot.) So the lion lets the cheetah do the hard work and reaps the benefits. “Lazy” or smart?

Cheetahs and lions may compete for some of the same food, but generally lions will go after larger prey, so a group of cheetahs is never going to wipe out all of a lion’s food sources. (Even if they manage to kill and eat their prey without the lions finding out.)

I’d say lions have more of a “rivalry” (if such a thing exists) with hyenas. If a hyena clan has enough of a numbers advantage they can chase off or even kill a lion, as well as defend their own kills. I just don’t think cheetahs are a threat to lions in the same way, apart from perhaps the odd cub.