A rat is a small mammal that belongs to the rodent family. It is known for its characteristic long tail and sharp incisor teeth. In the context of the clue "Fink," it refers to someone who is considered to be a informant, betrayer, or a person who reveals secrets or confidential information.
Note: The provided meaning of the answer is for the latest New York Times crossword puzzle clue: Sewer scurrier. Explanations are generated by AI and may be inaccurate.