Andrew Mulligan is Little Bill's best friend and he loves to have fun. Andrew is a five-year-old boy. When Andrew's family moved two doors down from Little Bill, they became fast friends. Andrew is as good at playing make-believe as Little Bill, and both boys share a love of adventure and Captain Brainstorm. Andrew has two older cousins, Rachel and Kevin, who sometimes visit and play with Little Bill, April, and Bobby. He also has a big, fluffy, lovable dog named Farfy.
Andrew is a ginger, he is always picked on and does far from excelling when it comes to anything physical. He also uses ketchup for shampoo.
Andrew is a red haired, freckled boy who is Little Bill's best friend. Andrew and Little Bill have many things in common - they both like Captain Brainstorm or play with construction sets, etc. In one episode Copy Cat Little Bill and Andrew had a quarrel and Andrew called Little Bill a copy cat, but soon learns his lesson and apologizes to him. Andrew has a pet dog named Farfy. Andrew is sometimes seen with his cousins: Kevin and Rachel. He lives two houses away from Little Bill. He is voiced by Zachary Tyler Eisen