Lord of the ThunderCats
The hereditary Lord of the ThunderCats, Lion-O is the son of Claudus, the ruler of Thundera at the time of its destruction. Initially a boy stuck in a man’s body, the years saw Lion-O develop the wisdom and skills needed to lead the ThunderCats on Third Earth, and later lead the rebuilding of his home world of New Thundera. Lion-O can be quick to anger, and is impulsive and headstrong, but also possesses great moral values, at the forefront of those being the Code of Thundera - Justice, Truth, Honour, and Loyalty. Lion-O is a fierce defender of freedom and a brave and noble leader, one that the other ThunderCats are proud to stand beside.
A boy in a man’s body
Lion-O was twelve when Thundera broke apart and the survivors fled in the flagship. The suspension capsules that carried them through the voyage slowed ageing rather than halting it, and he emerged on Third Earth with the body of a grown warrior and the experience of a child. That gap is the engine of the whole first season. He has the strength to lead long before he has the judgement, and almost every early defeat traces back to him acting first and thinking second.
Jaga, who died piloting the ship and returns as a spirit, is the one who keeps closing that gap. Panthro and Tygra stand in as the adults he measures himself against, and Tygra is named as his second, the one who would take the title if Lion-O did not return.
The Sword of Omens and the Claw Shield
The Sword of Omens rests as a short dagger and extends to a full blade in his hand. Set into the hilt is the Eye of Thundera, the source of the ThunderCats’ power and the thing every enemy on Third Earth is ultimately reaching for. Raised to his eyes it grants Sight Beyond Sight, showing him distant or concealed events. Raised overhead with the call of Thunder, Thunder, Thunder, ThunderCats Ho, it throws the Eye’s signal into the sky and surges the strength of every ThunderCat who sees it.
The Claw Shield on his left arm is the Sword’s scabbard in dagger form, and doubles as a shield, a grappling line and a smoke dispenser.
The Sword is not indestructible. In All that Glitters, Mumm-Ra manipulates Lion-O and Tygra into fighting one another, and Tygra’s bolo whip breaks the blade in two.
The Anointment Trials
To be confirmed as Lord of the ThunderCats, Lion-O has to defeat each of his companions in turn at the thing they are best at. Panthro takes the Trial of Strength, Cheetara the Trial of Speed, the ThunderKittens the Trial of Cunning, and Tygra the Trial of Mind Power. The final trial is the Trial of Evil, fought against Mumm-Ra inside the Black Pyramid.
The trials are the series being honest about its own premise. Lion-O does not inherit the role, he earns it one contest at a time, and in the Trial of Speed Cheetara is offended at the suggestion that she might let him win. The Code of Thundera does not allow it.
Across the series
Lion-O is the only character to appear in all 130 episodes, from Exodus through to The Book of Omens. He faces the Mutants under Slithe, the Lunataks, and above all Mumm-Ra, who he appears to destroy more than once and who returns every time.
