Arnold Jackson

Arnold Jackson
Arnold is a classmate of the girls, and is apparently the stereotype of the school's geeks and nerds. Arnold is highly clever but socially inept, and tends to be a bit unpleasant. In some episodes, he acts as a sycophant and minion of Mandy's, yet in other episodes he gets teased by her. He mostly acts as an (unintentional) obstacle to the girls and their goals.

In the episode "Super Nerd Much?", Arnold accidentally acquired a magic ring that allowed him to steal the "coolness" from other people. The power quickly got to his head, and he turned into a super villain intent on draining the coolness from everyone else in Beverly Hills, causing them to turn into nerds themselves. After a fight, he was eventually defeated by the girls with some assistance from a villainous magician who also wanted the ring. Like Mandy, his memory appeared to be erased by WOOHP and he was back at school the next day as though nothing had happened (albeit with a few residual memories he wrote off as part of a dream). He has also managed to defeat Clover and Mandy in contests for Head Cheerleader.

In the episode "Arnold the Great", he wants to be a superhero and dresses up as a comic book character. He is secretly taken advantage of by Geraldine Husk.

In the opening episode of Season 5 "Evil Graduation Much", Arnold graduated from Beverly High as the class valedictorian. In his graduation speech, he told off the entire senior class for mistreating him over the years, and left with the words "Goodbye, and good riddance!"

Robert Tinkler, Jess Harnell and Joshua Seth have all shared the voice of Arnold.