Despite having carried out many high-paying cons and robberies during the series, he and his criminal counterpart Hercules Grytpype-Thynne always appear to be permanently destitute.
Moriarty's deterioration was accompanied by a change in the character's voice, becoming higher in register and losing its smooth diction as the series progressed.
With his thick faux-French accent, he is often found scavenging in dustbins looking for food and uttering nonsensical, half-French curses such as "Sapristi nabolas!
(incorporating an old-fashioned French expletive that meant originally "by the body of Christ") and "Sacre Fred!"
Grytpype often introduces him ("and I quote from his death certificate") with a middle name such as "Thighs", "Knees", "Kidney Wiper", etc., along with an appropriate sound effect (e.g. rattling bones, swannee whistle) or Moriarty's catch-phrase "Oooowwwwww", and descriptions of his prowess in various fields: There is also some suggestion that the character is a parody of the Sherlock Holmes villain, Professor Moriarty.