Entrusted as Lion-O's guardian and respected by the whole of Thundera, Jaga spent much of his life as the primary aid of Claudus, the last Lord of the ThunderCats prior to Thundera's destruction. Wielding the mystic Sword of Omens, Jaga proved to be a nemesis to the forces of evil, both those within Thunderian ranks and (more commonly) the evil Mutants of the planet Plun-Darr. Calming and gentle, yet able to assume authoritative command of a situation at a moment's notice, Jaga possessed great leadership quality.
Revered as their elder by all of the ThunderCat nobles up to his transcending to the Astral World, Jaga's wisdom lives on as the spiritual advisor to Claudus' son Lion-O, the hereditary Lord of the ThunderCats.