Thagomizer

Found on Wikipedia: Thagomizer

The term "thagomizer" was coined by Gary Larson in a 1982 Far Side comic strip, in which a group of cavemen in a faux-modern lecture hall are taught by their caveman professor that the spikes were named "after the late Thag Simmons". The term was picked up initially by Ken Carpenter, a palaeontologist at the Denver Museum of Nature and Science, who used the term when describing a fossil at the Society of Vertebrate Paleontology Annual Meeting in 1993.

I have long held this as one of my very favorite cartoons ever, but I was surprised to learn it has been picked up as as an scientific informal term. This is not Gary Larson's only contribution to science; he has an owl louse named after him too (perhaps two other insects).