In this episode, we learn Thing's complete name: Thing T. Thing. Yes, the middle initial stands for "Thing"!
(prior to leaving in their car to take Thing to a concert)
Gomez: Tish, where will Thing ride?
Morticia: Darling, where he always rides - in the glove compartment.
Gomez' detective hat, pipe, and magnifying glass are clear allusions to the famous Sherlock Holmes.