Watch ThunderCats Season 1 Online

Lion-O, always outdone by his adoptive older brother Tygra, undergoes the ritual to be chosen by the Sword of Omens as the next king of Thundera. His father, Claudus, does not feel his son is ready because he is too lenient and easily distracted by flights of fancy like the myth of ancient technology. Soon after, King Claudus welcomes the return of his friend Grune and holds a celebration in both his honor and in memory of the fallen Panthro. During the event, Lion-O defends a pair of captured Lizards and convinces his father to release them.