Sean Maguire originally passed on the part because he wanted to do a more serious project following his role in the poorly received 2008 comedy film Meet the Spartans, and did not think the show was right for him; he also said he thought the title sounded stupid. Maguire said, "I thought, 'Who’s going to watch this piece of shit?' ... I’m too quick to judge." His manager encouraged him to read the script and give it another chance and, upon reading the script, Maguire changed his mind and decided he wanted the role. Maguire worked out two hours a day for three months prior to filming the first season in order to build up his physique for the role. The dynamic between Mändoon and Aneka was in part inspired by an idea Knight and Johnson had for a comedy set at a workplace, where a man and woman break up but have to see each other every day at their work setting; Maguire said he felt that aspect of the relationship gave Mändoon a very "human element" and was easy for male audiences to relate to.
India de Beaufort became familiar with Kröd Mändoon at an acting studio where she was receiving training. The teacher, who had read and loved a Mändoon script, brought it to the studio and told the students about it. Many of them tried to audition for the show, including Beaufort, so the role of Aneka proved to be a competitive one, but Beaufort eventually got an audition which led to her casting. When she agreed to take the role, she had only read the script for the first episode, "Wench Trouble", and did not know about some of the character's more promiscuous scenes in future episodes, such as her striptease dance in "Golden Powers". Upon learning more about the character, Beaufort became concerned that the role was too sexual and that she would not be taken seriously as an actress after playing the part. However, she said she quickly grew to love the character, who she believes to be a strong female character with feminist convictions: "She's saying, 'I'm equal to every other man in the world. Men enjoy sex. I enjoy sex.' You know, she's out there putting out this strong statement."
Matt Lucas said he sees the Dongalor character as a combination of Cambodian leader Pol Pot and James Bond antagonist Ernst Blofeld.
Chris Parnell, a comedian formerly of Saturday Night Live, provides the voice of the narrator in the North American version. Michael Gambon narrates the UK version.