Someone who likes to transportworthless gossip between others in a way similar to a drug mule transporting drugs.
Oswald: "Did you hear about how Bob is telling everyone that Jaquan got expelled?"
Charles: "Bruh Jaquan is just in Puerto Rico he'll be back next week. Bob is such a drama mule!"
Johnny knew it all too well. When he travelled, dry ass-brownies would slowly form. He would soon become excrementally challenged. He turned to a friend who, in turn, prescribed a Metamucil Mule.