Why is the sweet tooth fairy phenomenon so addictive? Nearly everyone can think them up, for one thing, and you get a satisfying pop of absurdity when one comes together. We all know how illogical and contradictory English can be, but sweet tooth fairies let us turn even the most banal and familiar parts of our language – sweet tooth, tooth fairy – into something strange and wonderful.

Erin McKean in The Boston Globe

A SATISFYING POP OF ABSURDITY

This is where all the proper sweet tooth fairy types are. The ones that follow the rules exactly. They are three words where the first and second words form a known expression, and the second and third words form a known expression, and all three words together make a credible expression.

Sweet Tooth Fairies

This is the only Sweet Tooth Fairy that lives on more than one list. When it was first used to describe these flighty figures of speech it was not a known expression. So it was just a Sweet Tooth Fairy. It has since perfected itself by becoming a known expression, and so is the only STF with a second home – now it’s a Perfect Sweet Tooth Fairy type. Hah!

sweet tooth fairy