1) Any body suspended in space will remain in space until made aware of its situation. (The character walks off the edge of a cliff, remains suspended in midair, and doesn't fall until he looks down)
2) Any body passing through solid matter will leave a perforation conforming to its perimeter (the "silhouette of passage").
3) Certain bodies can pass through solid walls painted to resemble tunnel entrances; others cannot. (Corollary: Portable holes work).
4) All principles of gravity are negated by fear. (i.e., scaring someone causes them to jump impossibly high in the air).
5) Any violent rearrangement of feline matter is impermanent. (In other words, cats heal fast and/or have an infinite number of lives) .
6) Everything falls faster than an anvil. (A falling anvil will always land directly upon the character's head, squashing him flat or driving him into the ground)
wwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwww- and weathered all that physical abuse over the seasons (some say he is the most physically abused cartoon character ever), the writers decide to give him a consolation which I am unhappy about -