alligator n. a piece of a rubber automobile tire (along a roadside). (source: Double-Tongued Dictionary)
Further reading
Don’t let your alligator mouth overload your hummingbird butt! is a more picturesque way of saying “Don’t boast!” This is part of a complete episode. Transcript of “Your Hummingbird Butt” I came across some excellent...
Alligator arms is a joking way to describe a tightwad whose arms suddenly seem too short to reach the restaurant check or a wallet. Bob from Minnesota uses it alongside a little menagerie of similar images: in Argentina, a miserly person may be said...