Larry is the extreme stereotype of a "nerd"; he is completely obsessed with several classic non-mainstream topics (comic books, science fiction movies and novelizations, and fantasy role-playing games). He exhibits poor social skills, at times has difficulty telling the difference between reality and fantasy, and has an extensive collection of action figures in his room.
Larry has helped Kim and Ron Stoppable during several of their missions.
The next instance of Larry helping Kim and Ron on a mission was when they needed access to the underground Robot Rumble to meet Vivian Francis Porter. Larry was a member of the Robot Rumble and Kim and Ron used him to gain access to the event. However, he was subsequently expelled from the club for bringing them in.
The last instance of Larry helping Kim and Ron on a mission was when Professor Dementor kidnapped Larry to try and obtain Kim's supersuit. Although, Larry believed that the entire thing was an elaborate role-playing game (RPG) scenario which Kim setup for his birthday.
He was also in Homecoming Upset, and met Queen Bonnie, although he did not do anything mission-wise in that episode. Ron, quickly got him out of there before she insulted him, like she has been insulting all of the guys, who attended "Meet The Queen." In this episode, he and Ron, were playing Netherworld, although not on screen.
Larry is an expert or knowledgeable in many stereotypical "nerd" topics such as comic books, science fiction movies and novelizations, fantasy role-playing games, computer games, and robotic fight clubs.
June is Larry's overprotective mother whom believes that he still has to be watched, which is why she always makes Kim hang out with him.
Ann Possible is Larry's aunt.
James Possible is Larry's uncle.
Kim, Jim, and Tim Possible are Larry's cousins.
Ron has also said that he chats with Larry from time to time and considers spending time with Larry to be fun.
Larry has a rivalry with Charlotte, a regular at the local comic shop. Although later he was seen going to the movies with her, but being rebuked when he tried to put his arm around her.
- While Larry shows an incredible breadth and depth of science fiction and fantasy knowledge he apparently doesn't read science fiction or fantasy novels since he tells Kim that he only reads novelizations.
- Customers in comic shop: "Larry!"
- Larry: "I request sanctuary for myself and this maiden (motions to Kim) in your dungeon."
- Customers: "Enter in Dragon Tamer."
- Larry (to Kim): "Standard greeting. We are welcomed."