As a child, Shaggy was essentially friendless, and convinced himself he liked the solitude. While talking to his imaginary friends he made out of the sand on the beach, he met a dog who had overheard his story and the two quickly became friends, bonding over Shaggy's love of unconventional sandwiches. One Halloween, two kids on skateboards throw Shaggy's candy inside of the Rigby house which is essentially haunted. Fred, Daphne, and Velma find them and head with them inside the house. While there, a so-called ghost starts chasing them around. They capture the ghost and he identifies as Mr. Rigby. They see all of his stolen goods and call the police. The police catch him and are called meddling kids for the first time and realize that they are good at solving mysteries and thus the start of Mystery Inc.