The main protagonist. Slylock is a quick-thinking detective who can unravel any mystery in a moment. He is known and respected among the locals and the police, who call him in on tougher cases.
- Cunning Like a Fox
- Detective Animal
- Expy: He's partially based off of Sherlock Holmes, as evident by his name and costume.
- Great Detective: Sly can solve most cases based on a single clue.
Slylock's loyal sidekick. Max isn't as quick to find answers as Slylock, and is often searching the backgrounds with a magnifying glass in hand. He has a tendency to wander into trouble.
- Bumbling Sidekick
- Nice Mice: Max is small, cute and friendly, as opposed to the villainous Reeky Rat.
- Your Size May Vary: He can range from toddler-size to a little above Slylock's waist.
The chief of police, who frequently calls upon Slylock and Max for assistance.
Tiffany Fox is schoolteacher and personal friend of Slylock. She occasionally calls him into her classroom as a guest speaker, and double dates with him, Max and Melody.
- Distaff Counterpart: To Slylock.
- Implied Love Interest: There's no solid evidence, but she and Slylock sure seem close.
Slylock's archnemesis is a green-skinned mad scientist, whose evil schemes are outright surreal. In addition to being a mechanical genius, he's often surrounded by bizarre monsters of his creation.
- Cut Lex Luthor a Check: He invented time travel and has never once thought to make money outside of crime.
- Evil Genius
- For the Evulz
- Go-Karting with Bowser: He and Slylock aren't always at odds, since some strips have shown him, Slylock, and Max all taking a trip to the past together in his time machine.
- Poke the Poodle: Among his lesser schemes is hypnotizing cowboys into dancing for him.
- Mad Scientist
An attractive but greedy feline. Cassandra is a would-be jewel thief whose sneaky tactics and convincing alibis never make it past Slylock and Max.
- Bitch in Sheep's Clothing
- Cats Are Mean
- Classy Cat-Burglar: Literalizes the metaphor.
- Faking and Entering: She's faked a burglary at least once in order to file fake a insurance claim
- Femme Fatale
A human thief and con man, who tries to weasel his way out of everything with a smug grin on his face.
- Con Man: Occasionally.
- Smug Smiler: Usually spotted with a toothy smirk and half-closed eyes.
- Token Human
A grifter and petty thief whose schemes Slylock unravels on a regular basis.
- Alliterative Name
- Con Man
- Perpetual Poverty: From what we've seen of his home, crime really hasn't paid for him at all.
A human witch who tends to target Max in her schemes.
A big gorilla that has a habit of robbing banks. His short, white-haired mama ape often offers false alibis for her felonious offspring.