Hopalong Casualty is a 1960 Road Runner cartoon directed by Chuck Jones.

Warning: Wikipedia contains spoilers.

In it, Wile E. Coyote as usual tries various devices to try and trap the Road Runner, all of which backfire. For instance, when he tries to trick the Road Runner into an Acme Parcel-making Machine, it is he who ends up neatly packaged.

Finally, in the cartoon's longest scene, he scatters some Acme Earthquake Pills on the road, hoping that the Road Runner will mistake them for birdseed. The Road Runner obligingly eats them, but they have no effect. In disgust Coyote swallows the entire bottle, noticing the small print only when it is too late: "Not effective on road runners". Then the pills take effect on him, causing him to shake, rattle and jerk helplessly across the landscape, getting flattened by a huge boulder and almost falling off a narrow rocky arch in the process.

When the pills finally wear off he is so relieved that he steps out without looking where he is going and strides off the edge of a cliff.

The Earthquake pills scene is also included in the Road Runner compilation that ends The Bugs Bunny/Road Runner Movie.