When looking for synonyms for "sly dog", terms like "cunning fox", "wily coyote" and "crafty cat" come to mind. Each of these phrases refers to someone who is clever and quick-witted, often with a hint of deception. Additional synonyms include "sneaky snake", "wily wolf", "sly fox", "shrewd crocodile", and "scheming raccoon". All of these phrases can be used to describe individuals who are quick-witted and clever, often with a mischievous streak. While these individuals may not always be trustworthy, they are often admired for their resourcefulness and ability to stay one step ahead of others.