1. Seems mighty chummy with the dog all of a sudden.
2. Unexplained calls to F. Lee Bailey's 900 number on your bill.
3. He actually *does* have your tongue.
4. You find a stash of "Feline of Fortune" magazines behind the couch.
5. Cyanide pawprints all over the house.
6. You wake up to find a bird's head in your bed.
7. As the wind blows over the grassy knoll in downtown Dallas, you get a faint whiff of catnip.
8. Droppings in litter box spell out "REDRUM."
9. Catch him with a new mohawk looking in the mirror saying, "Mew looking at me? Mew looking at me punk?"
10. Takes attentive notes every time "Itchy and Scratchy" are on.
11. You find blueprints for a Rube Goldgerg device that starts with a mouse chased into a hole and ends with flaming oil dumped on your bed.
12. Has taken a sudden interest in the wood chipper.
13. Instead of dead birds, leaves cartons of Marlboros on your doorstep.
14. Ball of yarn playfully tied into a hangman's noose.
15. You find a piece of paper labeled "MY WIL" which says "LEEV AWL 2 KAT."
16. Now sharpens claws on your car's brake lines.