This film sets the record for the most makeup appliances used in a single film. The numbers are staggering, totaling 22,541 prosthetics, 500 wigs, and 117 pairs of contacts by the end, used across more than 1,000 actors.
Taika Waititi was widely rumored to take over directing from James Gunn after the latter was temporarily fired from the project. However, Waititi made it clear that this option was never on the table for him, claiming that "those are James' films. [That] would be like going into someone's house and saying 'Hey, I'm your new dad, and this is how we make peanut butter sandwiches now.' It feels kind of awkward."
After James Gunn was fired as director, actor Dave Bautista (Drax) became one of Gunn's most vocal supporters, tweeting that "James Gunn is one of the most loving, caring, good natured people I have ever met. He's gentle and kind and cares deeply for people and animals. He's made mistakes. We all have. I'm NOT ok with what's happening to him." Bautista even stated that he would demand to be released from his contract if the studio did not use the screenplay Gunn had originally written for this film. Gunn was later re-hired.
Maria Bakalova did all the motion capture for the character she voices, Cosmo the Russian space dog. "She was crawling around on her hands and knees for all of these scenes playing her in person."
James Gunn and Chukwudi Iwuji worked to make the High Evolutionary a dark, irredeemable character, focusing on his traits of "single-mindedness, narcissism and zealotry - traits held by the most horrific figures in history."