Andy's first and most famous prank was when Andy was a student at Springfield Elementary School, and Seymour Skinner loved to swim in the school's early swimming pool (revealed by Groundskeeper Willie). Andy filled the pool with worms and locked Skinner in the pool for a whole weekend, including Monday, a teacher's holiday. The prank was named "Night of the Wigglers".
Later, Bart and Milhouse meet Andy and learn that he is unemployed and lives with his mother. Bart gets Andy a job to be Krusty's advisor, but he quits after his first day because Krusty was bossing him around. Andy later gets rehired by Krusty, but Bart is worried when he sees a worm truck driving into the studio. Bart thinks Andy will repeat the "Night of the Wigglers" prank, but it turns out that he got worms for Krusty's act of falling into a pool of worms. Krusty made Andy his writer, and is now employed.
Currently, Andy is still writing for Krusty. He also has a girlfriend who works for Krusty in the makeup department (which she calls the "makeout department"). Andy still lives with his mother, but thinks that it's fine.
He was named after Andrew "Andy" Hamilton of Chicago, Illinois who was the first fan to email the writers after Homer revealed his Email as Chunkylover53@aol.com in the episode "The Dad Who Knew Too Little".