Lions are large cats native to Africa and Asia and present in Clan mythology.
Lions live in groups called prides, often with only one or two adult males, an assortment of females, and a number of cubs of both genders. Females often stay in the pride they were born in, but males are expelled from it upon reaching adulthood.
Lions display sexual dimorphism, meaning male lions and lionesses show obvious differences. Both genders, however, are very large, typically with golden or sandy-colored fur, though at times this color can be reddish or brown. Lions have broad muzzles and black tufts of fur at the end of their tails.
Male lions, with some exceptions, have thick manes of long fur extending from the top of their heads down their back and chest. These manes can vary in color from white to sandy blond to black, usually darker depending on the age of the lion. Lions with darker manes typically attract more mates than those with lighter manes as a darker mane also indicates a higher level of testosterone, indicating the lion to be a better fighter and protector than those with lighter manes.
Female lions, or lionesses, are slightly smaller than male lions and lack a mane, though they are notably more aggressive than males. Where lions protect the pride from outside threats, lionesses hunt and provide food for the pride. 
Lions are among the few in the Felidae family to live primarily in groups and hunt in packs. Lion cubs stay with their mother for two years, and the pride's cubs are cared for by all the females, so that when a mother lionness is out hunting, another female can feed her young. Between fourteen and seventy-three percent of lion cubs die before reaching two years of age.
Relations to Clan Cats
Lions are present in Clan mythology as LionClan, an ancient Clan of the big cats that had manes like rays of sun.
When Thistlepaw successfully chases off a dog, Mumblefoot remarks that no Clan cat attempted to do such an act since LionClan roamed the forest. When Sunstar calls for a Clan meeting, he promises to make ThunderClan be remembered alongside TigerClan and LionClan.
Whitestorm talks about prey with Bluestar, commenting that if wishes were prey, they'd eat like lions come leafbare.
The night before going to battle with TigerClan, Firestar spends the night outside of camp reflecting on his chances of winning the oncoming bout. When he goes to get a drink of water, he sees a lion instead of his own reflection, inspiring him to create LionClan out of ThunderClan and WindClan.
When Brightheart speaks of Swiftpaw's death, she remembers him fighting like all of LionClan. As Tawnypelt recounts on the end of the Journey to Midnight, she thought that LionClan's giant cats were prowling out of sight. When Cloudtail recounts on his rescue by Fireheart, he feels as if all of LionClan had came to rescue him. In the section "Prophecies and Omens", it mentions that Fireheart once say a reflection of a lion in a pool of water instead of his own, which prompts him to create LionClan. In the prophecy's respective section, Firestar explains how he gradually learned that he learned that LionClan and TigerClan would meet in battle, and they had to unite to drive out BloodClan.
LionClan is described with flowing manes like that of the sun's rays. In the story "How LeopardClan Won the River," Goldenstar, LionClan's leader, speaks of a boar in the forest.
In the story "How Snakes Came To The Forest," a LionClan warrior named Sunpelt, who is said to have heard stories of a hostile snake named Mouthclaw. Although cats from all Clans are forbidden to go to Snakerocks, Sunpelt believes that he would earn the forest's respect if he kills Mouthclaw. One morning, Sunpelt angers Mouthclaw by kicking stones into her cave so she can come out, and she bares her fangs, as she favored LionClan warriors for a meal. She lunges for Sunpelt, but he leaps from rock to rock. The two fight throughout the day before Mouthclaw requests Sunpelt to spare her for a wish, and he wishes for her to shrink herself. Once she turns into a thousand small snakes, Sunpelt, horrified, returns to camp to report his deed. Goldenstar, although displeased at the amount of snakes, notes that none of them would be as dangerous as Mouthclaw, and forgives Sunpelt.
In "How TigerClan Got Their Stripes," LionClan and TigerClan are both said to have golden coats, but LionClan had long manes like the sun's rays. One day, Thorntooth, a TigerClan warrior, steals Petalkit, a LionClan cub, and Shadestar is enraged at his actions, as LionClan would war with TigerClan until Petalkit was given back. That night, Shadestar calls for a Gathering to give Petalkit back to her father, Goldenstar. Thorntooth wishes that TigerClan had something to set them apart from the other Clans, and Goldenstar punishes TigerClan to forfeit their honor for a moon.