The Spider-Clown Mailman was first seen in Billy & Mandy's Big Boogey Adventure.
The Hand created Billy's fear and a truck comes and out comes a person with six black spider arms (two spider arms had fingers) with spider jaws and purple body and eyes, orange clown nose, green hair, red lips with sharp teeth, and yellow and white pants and shoes, and with a blue mailman hat with package. He grabs Billy and blows his nose and makes a pony and laughs. Mandy shoots the Spider-Clown Mailman, but it shows that Billy has to fight his own fear.
- It is combined of Billy's true fears, a spider, a clown and a mailman though there was never any explanation even in the series as to why Billy even has a fear of the mailman.