The moggy has been pinching everything from underwear, baby clothes and even a German sausage.
His owners, Richard and Sophie Windsor, were at first confused when the selection of goodies - including a bath mat, a towel set and even a tube of gravy paste - started turning up at their doorstep.
But when their pet wandered in with a half a pizza, they realised he must have taken it from someone.
Richard, 26, said: "He was perfectly well-behaved until the age of one, then he started to turn to a life of petty crime.
"At first it was just the odd thing - but over the last four months, he has really upped his game."
The couple have even been forced to write letters to their neighbours to apologise for their thieving feline - and asking anyone who is missing something to get in touch.
The letter read: "Dear neighbours, This is slightly embarrassing but our cat, Norris, has taken to theft. If you have 'misplaced' anything please give us a nudge. We'll have a dig through his horde and drop them back to you."
Richard said: "It is not as if they are high-value items, but they belong to someone. So far we have been able to reunite a number of items with their owners."