Conrad Mundy (often called by his last name) is a bad kid who, according to Gretchen, is the second worst kid at Third Street School. As a result of his bad behavior, he is a frequent visitor to Principal Prickly's office.
In the episode "Mundy, Mundy," he prevents a ball from hitting Cindy, Mundy becomes quite popular due to this, much to his chagrin. In the episode "The Girl Was Trouble," Gretchen told him how to get the tissue paper to stick to the ceiling of the bathroom so that, in exchange, he would tell Gretchen to whom he had traded Galileo.
In the episode "Gus and Misdemeanors," Mundy and two of his friends, Skeens and Lazy Kid, trick Gus into stealing from Kelso's. Afterwards, they bring Gus to their secret creek. In the episode "Kurst the Not So Bad", Mundy, along with Skeens, Lazy Kid, and Sue Bob Murphy, steal huckleberry cobbler from the school cafeteria.
Mundy has made numerous cameo appearances in several episodes. For instance in the episode "The Madness of King Bob," he was in the angry crowd in front of the playground. Moreover, he made a few other appearances in the episode "The Ratings Game" at the beginning and the end of the episode. In the episode, "The Biggest Trouble Ever," he tells T.J. and the rest of the gang that he wishes he could've done something so bad that he would've landed on the news.
- Conrad's appearance is based on Lampwick from Disney's Pinocchio.
- Conrad is quite similar to Stuart Dooley from the television show King of the Hill.
- In the episode "The Ratings Game," Mundy is shown to be 5, however, towards the end of the episode, Mundy said (returning to the back of the school) "I missed you man" to Skeens, who was also given a 5.
- In "Dodgeball City," he can briefly be seen on the fifth grade side during an overhead shot of the court. However, later on, we see him with the fourth graders in jail. It is unknown if he is in fourth or fifth grade, though the latter is more likely that his friends Greg Skeens and Sue Bob Murphy are fifth graders.
- In "The Biggest Trouble Ever", it is revealed that his first name is Conrad. It is also been revealed that there is a dream of his of doing something so rotten that he will be on the news. He congratulated The Recess Gang after they destroyed the statue of Thaddeus T. Third III.