Jemaine Clement is joining the cast of James Cameron’s “Avatar” sequels. He will play marine biologist Dr. Ian Garvin.

“I’ve loved Jemaine’s work for years and I’m really pumped that he’s joining our cast as Ian Garvin, one of my favorite characters,” Cameron said in a statement.

“Avatar 2,” the first of four follow-ups, will hit theaters on Dec. 17, 2021, a year after what Fox had planned before it was bought by Disney in March. Disney announced last week that the remaining installments will be released on the same weekend every two years, alternating with “Star Wars” movies with “Avatar 3” arriving in 2023; “Avatar 4” in 2025; and finally “Avatar 5” in 2027.

The 2009 fantasy epic “Avatar” remains the all-time box office champion, with $2.8 billion worldwide. Cameron initially envisioned two sequels, but after meeting with the screenwriters, artists and designers, realized he had too much material and extended his plans to four movies in total.

Cameron and Jon Landau are producing through their Lightstorm Entertainment company. Zoe Saldana, Sam Worthington and Sigourney Weaver are returning for the upcoming films. Michelle Yeoh, Kate Winslet and “Game of Thrones” actress Oona Chaplin have also joined the cast. The script was written by Cameron with Josh Friedman, Rick Jaffa, Amanda Silver and Shane Salerno.

Clement is the co-creator of FX’s comedy series “What We Do in the Shadows,” based on the 2014 vampire mockumentary. He also starred opposite Dan Stevens in FX’s drama series “Legion.” Clement’s other credits include “An Evening with Beverly Luff Linn” and “Brad’s Status” with Ben Stiller.