Mack was a Hexford College porter who resided in the same lodgings as Henry Cleavis and John. It transpired that Mack was a Gyregoyle - a giant bat-like creature - who ransacked the pair's quaters while they were away at one of Reginald Tyler's parties. Cleavis and John confronted Mack upon their return to which he demanded Cleavis turn over his completed manuscript. A brief altercation led to Mack being impaled by John with a broken cricket bat, before fleeing into the night sky.