The film begins with the Hostile Tribe, led by the formidable Tonda (John Matuszak), whose sheer size and strength crown him as the unquestioned Alpha male. In stark contrast to his robust leader is Atouk (Ringo Starr), the smallest and weakest member of the tribe. As he scuttles about, desperately searching for sustenance, Atouk becomes the target of mockery and bullying from his peers, perpetually pushed from tree to tree. His moment of hope—or rather, a small lizard he nearly catches—is shattered when a looming shadow reveals the true predator: a massive dinosaur. Frantically, Atouk warns his tribe, causing them to flee as the dinosaur wreaks havoc, uprooting trees and snatching away Noota, a fellow caveman, for its devouring pleasure.
Upon returning to their cave, the tribe's frustration is palpable, and they collectively blame Atouk for their misfortune. Amidst the chaos, Atouk’s empathetic nature shines through as he tends to his injured friend, Lar (Dennis Quaid), who had attempted a valiant but futile defense against the dinosaur. His act of kindness, however, is overlooked by the tribe's leaders, who perceive Lar as "Pooka" (hurt or 'broken'). Abandoned and weighed down by guilt, Atouk occupies a lonely corner of the cave, where his creativity bursts forth as he creates drawings—a flicker of hope amidst despair.
As hunger pervades the atmosphere, Atouk is struck by admiration for Lana (Barbara Bach), Tonda's enchanting mate, who is equally distressed over the tribe's lack of food. His selflessness shines again when he offers her a fruit—only to find it back in Tonda's hands shortly after. During another food-gathering expedition, the tribe becomes suspicious of a tree draped in berries, and inevitably, Atouk is seized as a test subject for their potency. The effect is euphoric, leading to a drug-induced slumber that gets him dragged back to the cave like an unconscious rag doll.
In a moment of unintended consequences, Atouk attempts to seduce Lana by offering her a concoction of the sleepy berries, but he inadvertently knocks out both her and Tonda while trying to ingratiate himself. Under the cover of night, he attempts to take advantage of the situation and create a romantic moment with her—an endeavor that inevitably fails when Tonda awakens, furious and vexed, ultimately banishing Atouk from the hostilities of the tribe.
Left to wander the wilderness, Atouk stumbles upon Lar, who has been hiding out and recuperating. Their reunion is nothing short of heartwarming; as they embrace, they discover newfound stature, literally standing taller and resolute. That night, they cross paths with Tala (Shelley Long) and her elderly companion Gog (Jack Gilford). Saving Gog from the clutches of a tar pit cements a budding friendship as Atouk and Lar heal the blind elder’s posture, signifying newfound strength and partnerships.
However, a series of slapstick misadventures ensue when Gog's blind curiosity leads him to interact with a rather large dinosaur. The bonds deepen as they manage to evade danger together, and with each thrilling moment, the unified Misfit tribe starts to form, highlighting the contrasting dynamics with Tonda's original tribe.
As the Misfits face various challenges, including a rainstorm that introduces them to fire, they construct their collective home while charmingly fumbling through several occurrences of culture shock—culminating in an amusing moment where they form the first primitive band session, harmonizing around a roaring fire.
Trials begin to mount as they find themselves continuously challenged by the Hostile Tribe and their leader, Tonda. The tension builds, leading to a humorous yet perilous chase triggered by food shortages and social rivalries. But the Misfits’ resolve strengthens, culminating in a quest when Atouk decides to infiltrate Tonda’s cave to reclaim stolen fire and fight for their identity as a tribe.
A whirlwind of comedic, chaotic encounters ensue, with Atouk ultimately seizing victory—having outsmarted Tonda and declared himself the new leader of the now-unified tribe. Yet, as Lana flutters toward him, Atouk makes an unexpected decision—casting her into a pile of dinosaur dung, symbolically jettisoning petty desires, now ready to accept Tala as his true mate.
In a triumphant finale, Atouk and Tala, now leaders of a harmonious tribe, celebrate their victory as comrades. The screen fades to black, leaving the audience with a charming message: “And they lived happily ever after,” as the credits roll, encapsulating the blend of humor, adventure, and the timeless struggle for acceptance.
