Saying “Watch me pull a rabbit out of this hat!” guarantees that the next thing to appear will be anything but a rabbit.
Corollary: Absolutely anyone, of any species, can look like a totally convincing really hot chick with just some fake eyelashes and a wig.
TNT is almost everywhere.
Getting smacked in the head with a 2"x 4", an anvil, or any other heavy object will result in a large, pointy bump at the place of said whacking. One can typically minimize the lump by pressing down on it, but with the consequence that the bump will reappear elsewhere on the body.
Also, as a corollary: No injury ever causes bleeding or blood loss.
When one attempts to run anywhere quickly, there is a period of time during which the legs/feet rotate furiously on the ground, without actually gaining any traction or achieving any motion, followed by an action not unlike being fired from a gun.
If you go crashing at speed through a wall or fence, you will leave behind a precise cut-out shape of your own physical form.
If ever something bad happens so that you are squashed, deformed or otherwise rendered completely flat, do not worry. A few seconds later, with some effort and an indignant ‘shrugging off’ action, you will be able to re-assert your normal form. This creates a sound much like some strained creaking followed by a cork popping from a bottle.
Painting a black arch on a cliff or a black circle on the ground will result in a hole – but not for you.
Gravity only works if you look down.
No matter what dirty tricks you try, the Thunderbolt Grease Slapper will cross the finish line first.
A frog can have a wolf as an uncle.
Martians look like bowling balls.
That’s a great essay - a lot of truth to the concept that Boomers were more likely to identify with the Roadrunner (the U.S. in the 60’s and 70’s was ascendant and we felt like we could do no wrong) while young folks today may be more likely to identify with the Coyote (he embodies a can-do spirit and better reflects the U.S.'s experiences in the world lately 
)…