[6] Lion-O is based on the lion and wields the legendary Sword of Omens,[7] which is able to fire bolts of energy and allows Lion-O to see across great distances with the embedded Eye of Thundera's power of "Sight Beyond Sight", as well as the Claw Shield, a gauntlet that launches grappling lines from its claws.
[9] In the latter half of the show's first season, Lion-O has to put all that he has learned to use in the "Anointment Trials", which consist of contests of strength, speed, cunning, and intelligence (this last is referred to as "mind-power" in the story arc) against each of the other ThunderCats.
(Complicating matters for Lion-O is the fact that he is required to be unarmed for the contests; moreover, the other ThunderCats are not permitted to assist him.
The Mutants attempt, but ultimately without success, to take advantage of this last condition in an effort to leave the ThunderCats leaderless).
Ultimately triumphing over Mumm-Ra in a final battle ("The Trial of Evil") in the heart of the villain's pyramid in which he discovers that Mumm-Ra, like any Egyptian mummy, is dependent upon his sarcophagus, Lion-O is crowned the true Lord of the ThunderCats in a grand inaugural ceremony attended by nearly every inhabitant of Third Earth.
[12] The 1985 version of Lion-O makes a cameo appearance in the film Space Jam: A New Legacy alongside Cheetara and other fictional characters.