We were expecting to see the returns of other stars from The Karate Kid movies, but there probably weren't many fans who pictured an appearance from Carrie Underwood. In the show's fourth season, which premiered on Netflix on New Year's Eve, the 7-time Grammy Award winner appeared to perform "The Moment of Truth" from The Karate Kid original soundtrack. The American Idol winner addressed her cameo and noted how thrilled she was to join the Miyagiverse.

“I grew up watching 'Daniel’ and ‘Johnny,’ and I can’t believe I actually get to be a small part of the legacy that is The Karate Kid," Underwood said. "Once I discovered Cobra Kai a few years ago, it became one of my favorite shows! I had so much fun being on the set and singing such a classic song. I cannot wait to watch every new episode!”

Season 4 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. As Samantha (Mary Mouser) and Miguel (Xolo Maridueña) try to maintain the dojo alliance and Robby (Tanner Buchanan) goes all in at Cobra Kai, the fate of the Valley has never been more precarious. What tricks does Kreese (Martin Kove) have up his sleeve? Can Daniel (Ralph Macchio) and Johnny (William Zabka) bury their decades-long hatchet to defeat Kreese? Or will Cobra Kai become the face of karate in the valley?

Carrie Underwood Joins Returning Legacy Stars

Carrie Underwood, William Zabka
Netflix

Carrie Underwood's appearance was rather unexpected, but there was a lot of hype focused on the return of Thomas Ian Griffith as The Karate Kid III villain Terry Silver. The character's comeback had been featured heavily in the season's promotion but fans will need to stream the episodes to see how he fits into the story. Cobra Kai has garnered widespread praise from fans and critics for the way characters from the past are written into the story in interesting and believable ways.

The main cast also includes Ralph Macchio (Daniel LaRusso), William Zabka (Johnny Lawrence), Courtney Henggeler (Amanda LaRusso), Xolo Maridueña (Miguel Diaz), Tanner Buchanan (Robby Keene), Mary Mouser (Samantha LaRusso), Jacob Bertrand (Hawk), Gianni Decenzo (Demetri), Vanessa Rubio (Carmen), Peyton List (Tory), and Martin Kove (John Kreese) with Dallas Dupree Young (Kenny), Oona O'Brien (Devon), and Griffin Santopietro (Anthony).

Cobra Kai is written and executive produced by Josh Heald, Jon Hurwitz, and Hayden Schlossberg via their production company, Counterbalance Entertainment. Will Smith, James Lassiter, and Caleeb Pinkett executive produce for Westbrook Entertainment along with Susan Ekins in association with Sony Pictures Television. Ralph Macchio and William Zabka also serve as executive producers.

Cobra Kai is now streaming all four seasons on Netflix. Many are saying that this is the best season yet, and the critics have unanimously praised season 4 with a perfect 100% score on Rotten Tomatoes. While the fifth season was wrapped last month, it's unclear when season 5 will premiere. Because filming is already in the can, let's hope the new episodes aren't too far off and will hit the streamer sometime this year.