“Toodles the cat celebrated his 18th birthday on St. Patrick’s Day in 1940. A stout 19 pounds, he is deaf and beginning to lose his teeth. Toodles is set in his ways and doesn’t like his daily routine interrupted, especially… his afternoon nap.” 1940. Source.
apparently Toodles and Tiddles are the same specific genre of cat
Terry Pratchett wrote Going Postal quite a long time after 1940, so perhaps Tiddles of the Ankh-Morpork Post Office is a descendant of this one.