Panthro the eldest, strongest and smartest living member of the ThunderCats, he's a mechanical wizard and engineering genius. His advanced fighting technique, with battle-sticks, gives him a reputation among the other ThunderCats and proves to make him a vital team member. His legendary mechanical knowledge helped him construct the Thunder Tank from pieces of their destroyed spaceship. After building Cats Lair with Tygra and the Robear Berbils help, Panthro was then able to build many new vehicles in his Technical workshop. He also speaks his mind. Is the genius behind the Dragon Armor and all their other gadgets and weapons. Panthro is invaluable to the war effort, not only for his inventions but for his skills in combat. Panthro created the other ThunderCats armor to be sleek, flexible and tough, but his own is not lustrous nor very flexible but built like a tank. It also has a backpack filled with everything he may require in the field.
In the 2011 Animated Series, Panthro is one of Claudus' more loyal soldiers who was sent by his friend Grune to find the Book of Omens. They attempted search resulted with Mumm-Ra's release and Grune betraying Panthro, who while fighting Grune fell down an abyss and seemingly was killed. However, Panthro survived and constructed the Thunder Tank, which he later used in order to Lion-O's group from Slythe's platoon. Though he questioned Lion-O's ability to lead, Panthro eventually accepted him as the new king. Unlike the rest of the ThunderCats, he never learned to swim. In "Between Brothers," Panthro duels with Grune when he and Slithe attack the Elephants' village against Mumm-Ra's orders. Panthro loses most of his arms while trapping Grune in the astral plane. He was later outfitted with mechanical arms built by the Berbils which can also elongate themselves. In "The Pit," it learned that he was an old friend of Dobo back when they were slaves in a gladiator arena called "The Pit" which was located in a city that is inhabited by Dogs. Panthro later escaped the Pit when it became apparent that the match the next day would be a death match. This caused Dobo to feel bitter towards Panthro until Panthro revealed the deathmatch would pit him and Dobo against each other. In "What Lies Above" it is revealed Panthro is afraid of heights, which he finds out during the Feliner's first flight.