Andrew "Andy" Hamilton is a former student at Springfield Elementary School and is said to be the best prankster ever. He is currently a writer for The Krusty the Clown Show. Bart Simpson saved Andy's pranking career by telling him that he has to grow up.
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 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"). However, Andy still lives with his mother, but he thinks it's fine.