“Cobra Kai: Season 4” (Netflix — season premiere, Dec. 31)

The fourth season of the original drama series finds the Miyagi-Do and Eagle Fang dojos joining forces to take down Cobra Kai at the All Valley Under 18 Karate Tournament — and whoever loses must hang up their gi. Cast returnees include Ralph Macchio, William Zabka, Courtney Henggeler, Xolo Maridue‘na and Tanner Buchanan.