Samukai was the secondary antagonist of the first year of Ninjago, beside Lord Garmadon and one of the antagonists in Day of Departed. He is a powerful four–armed giant skeleton who was the ruler of the underworld until Garmadon arrived and dethroned him by besting him in a duel, and currently the leader of the skeleton army. Samukai and his men are looking for four golden weapons that grant great power, and ultimately he and Lord Garmadon defeat the ninjas and take the weapons from them. However, instead of giving his master the weapons, Samukai betrays Garmadon and tries to use the weapons himself, only to be destroyed by their power. He is the first character in Ninjago to actually die.
The actual figure of Samukai is the rarest and most expensive in the Ninjago toyline, as he only appears in the two largest sets of the first year's series and does not have a spinner unlike every other character. As a result, he regularly sells for at least 20–30 dollars online.
Many years after his death, Samukai was finally resurrected by Sensei Yang with Cryptor, Morro, Kozu and Chen to destroy the Ninjas. He eventually was defeated and sent back into the dimension or lived all the dead of the realms.