Most of the Guardians fans know and love are back for the special. Pratt plays Peter, Bautista plays Drax the Destroyer, and Klementieff plays Mantis. Bradley Cooper once again voices Rocket, and Vin Diesel is the voice of Groot. Groot appears much older than he was when we last saw him in "Love and Thunder" and is no longer a teenager. Gunn said on Twitter that fans started calling him "Swoll Groot" after seeing the teaser for "GOTG 3" at Comic-Con in July, so he started calling Groot that, too.
Karen Gillan is also back as Nebula and Sean Gunn (whose brother is the director) returns as Kraglin Obfonteri. Cosmo the Spacedog is also back, this time voiced and motion-acted by Maria Bakalova. And, of course, Bacon, who Starlord is obsessed with in the first movie, plays himself. Gunn joked on Twitter that within MCU continuity, Bacon stars in movies like "Footloose," "Cocktail," and "Eternal Sunshine of the Spotless Mind."