He is voiced by Hiroaki Hirata in the Japanese version, and by Paul St. Peter in the English version and returned to reprise his role in Digimon Adventure tri..
He resembles a humanoid lion warrior that weilds a mighty sword.
Leomon went face-to-face with his rival, Ogremon, he was infected by Devimon's Touch of Evil, turning him evil. Luckily Tai and Matt raised their Digivices and released the Black Gears from Leomon's body, returning him to normal.
Later, he returned as SaberLeomon to rescue Mimi and Joe from MetalEtemon. He challenged MetalEtemon to a battle as SaberLeomon, but was fatally wounded by MetalEtemon's attack. Using the last ounce of his strength, SaberLeomon pierced through MetalEtemon's damaged armor (which was punctured by Zudomon's Vulcan Hammer attack. In his dying breath, Leomon said that he will be reborn in Primary Village and hope to greet Ogremon once more now as allies instead of enemies.
Digimon Adventure tri.
Leomon protects Elecmon and Primary Village from an infected Ogremon, who has broken the Digi-Eggs. Ogremon injures Leomon and then runs away, with the latter giving chase. Their fight is observed by the Digimon Emperor.
Leomon show up in Real World to stop Ogremon to protects Daigo Nishijima, Maki Himekawa and take Ogremon back to Digital World. Tai then arrives with Leomon, who informs them of the terror the infection has unleashed on the Digital World. He decides to aid them as best he can between the worlds. Left alone, Leomon is weakened by Meicoomon's cuteness to allow them to go to the school. The Digimon desire food but lack the money, so they enter the "Creepy-Cute Costume Contest" to win free food, which draws the DigiDestined to the scene. Leomon ends up attempting to fight off an infection, leaving Palmon and Gomamon to try with deal with the Imperialdramon who appears under the Digimon Emperor's command.
Rosemon amd Vikemon united with Leomon who has fought off his infection, defeat Imperialdramon and rescue Meicoomon, but they fail to apprehend the Digimon Emperor. Reunited, everyone wonders what has happened to Ken to make him take the persona of the Digimon Emperor again. As the fully reunited DigiDestined discuss their next plan, Meicoomon appears to confuse Leomon with his infected form. Meicoomon tears Leomon apart to the DigiDestined's horror, though Himekawa has a smirk unseen by the others.
Digimon Adventure tri.
- Leomon dies two times.
- He is the fourth and last Digimon to sacrifice to save DigiDestined from Villains.
- His English Voice Actor, Paul St. Peter also voices Apocalymon from Digimon Adventure, Cherubimon, Diaboromon from Digimon: The Movie, Wormmon, Stingmon, Tapirmon, Paildramon, Imperialdramon from Digimon Adventure 02, Leomon from Digimon Tamers, Kurama from Naruto/Naruto Shippuden and Tritor from Power Rangers Zeo.