Molloy is a cat burglar who lived at the Springfield Retirement Castle.
He started a crime wave in Springfield, that ended with the world's largest cubic zirconia being stolen, which led to his arrest. He mentioned having been a cat burglar for years. He then tricked the entire town into going on a phony treasure hunt, and he escaped from Springfield State Prison during it.
Molloy was also a suspect when the zirconia went missing a second time.
A wanted poster of Molloy can be seen on occasion in the Springfield Police Department.
 Stolen items
- Bart's portable TV and stamp collection
- Lisa's saxophone
- Marge's necklace
- Flanders' Shroud of Turin beach towels
- Skinner's Stormin' Norman commemorative plates (which had been previously stolen)
- Selma's lock of MacGyver's hair
- The world's largest cubic zirconia