Though he appears human, he seems to have little actual knowledge of everyday life on Earth. Though exceptionally vain, especially about his blond hair (actually a wig), he is nevertheless a highly competent Galactic Guardian.
He is often assigned to deep space patrol, and secretly covets Betty's rank as the top Galactic Guardian due to the fame and recognition it brings. As such, he often goes around and brags to Betty's friends (both on and off Earth) that he is the hero, and the actual secret behind Betty's success and reputation. Even with this he sometimes assists Betty in her times of dire need and gets along well with her and her friends on Earth, making him not so much a villain but a mischievous character. He also has a crush on Betty. He isn't aware that Betty has a mild dislike for him though sees him as a friend. The people of Betty's home planet doesn't know that Betty is a Galactic Guardian and she's trying to keep this a secret. He has a huge ego and this once cost him his job after he tried to make a gold statue.
Despite that, he has a good heart as he saved Betty from his evil brother.
Atomic Roger reported to Galactic Guardian Headquarters to see DeGill, (actually DeGilla) who as he observed, looked a bit stranger than normal. The supposed DeGill said that Roger had nice hair and asked if he would like to join a new army. (Night of the DeGilla Monster)
In Betty's Secret Admirer, Roger is revealed to have a twin brother Dodger who is criminal seeking vengeance for his brother being fired after he stole gold. Dodger masqueraded as his brother and made it seem like it was an act of love for Betty, since he knew Roger liked her. After Dodger revealed his plan to destroy galactic HQ with a monster, Roger appeared and saved Betty, revealing Dodger's act. Once Betty defeated the monster, she gave Roger credit for helping her and he is reinstated as a guardian, to his delight.
- Roger is similar to Captain Zapp Brannigan from Futurama. Both are members of the peace-keeping force in the galaxy, the Galactic Guardians in Roger's case, and the Democratic Order of Planets (D.O.O.P.) in Zapp's case. Both are vain, selfish and proud of their blond hair, which in both character's cases, is actually a wig. Both are well-acquainted with the female protagonist of the series, Atomic Betty in Roger's case, and Captain Turanga Leela in Zapp's case, sometimes helping them or being antagonistic towards them. However, while Zapp is very attracted to Leela and makes that point clear nearly every time they meet, Roger only may or may not have a crush on Betty.
- Dwayne Hill provided his original voicing work of Atomic Roger, while he is also best known for voicing the titular role of Norman Picklestripes, the main character of Universal Kids' stop motion-claymated musical series, as well as being the voiceover heard in YTV's short-lived game show, Uh-Oh! (with Wink Yahoo) and the Coffee Guy in the Totally Spies! Season 3 episode, "Evil Coffee Shop Much?".
- On the final season, referred to as Atomic Betty: Mission Earth, Hill provided the different voice of Minimus P.U. and Spindly Tam Kanushu, right after Len Carlson's death in 2006.
- Atomic Roger (Season One, Episode 105b)
- Betty's Secret Admirer (Season One, Episode 113a)
- Dr. Cerebral and the Stupifactor Ray (Season One, Episode 124b) (cameo)
- Evil Idol (Season One, Episode 126b) (cameo)
- Earth to Roger (Season Two, Episode (208b)
- Hi-Jinxed (Season Two, Episode 209a) (cameo)
- Night of the DeGilla Monster (Season Two, Episode 218b) (cameo)