etymology
What is the etymology of the phrase "one trick pony"?
Can ponies do tricks?
Oxford doesn't any etymology info.
Wiktionary doesn't provide any info either besides the definition:
A performing animal (especially a pony) that knows only one trick.
(idiomatic, by extension) A person or group noteworthy for only a single achievement, skill, or characteristic.
I'm partial to the shift key+z typo answer.
If you're typing OMG really fast (cause you're so excited) you're going to slip and hit zOMG, since the < key isn't between shift and Z on most US keyboards.
Outside of any of the other possible origins, the typo is the most likely because it's most easily 'discovered' by small groups of people who are instant messaging each other. Most likely it has risen out of a parallell evolution because of our natural tendencies (as opposed to being invented or "first coined" by anyone).
Essentially, we all invent it ourselves.
IMO, the verb form of favorite would have slowly started becoming popular at around the same time that Microsoft Internet Explorer did. The Wikipedia page for bookmark states:
Bookmarks are called favorites or Internet shortcuts in Internet Explorer, and by virtue of that browser's large market share, these terms have been synonymous with bookmark since the first browser war.
The first browser war took place between 1995 and the early 2000s.
Internet Explorer 1 was a reworked version of Mosaic and was released in 1995. Among its many customisations, the Bookmarks menu was renamed to Favorites.
Best Answer
A pony that only knows one trick.
Yes. Especially in circuses.
Indeed the OED gives for the literal definition "esp. one performing in a circus" which strikes me as amusing; let's make sure a pedant who finds a one-trick pony outside of a circus doesn't prove us wrong!
Anyway, their first quotation is:
This from the Oregon Pioneer Association 32nd Ann. Reunion published in 1905. While there may be a degree of figurative use (it would be pedantry to correct them if you found out that this circus had in fact had two clowns, and didn't actually have a pony at all), it is still using "one-trick-pony" to refer to a small horse that has been taught a single trick.
Now, kids today with their games-consoles and their boy-bands and their player-pianos might not be particularly impressed by circus ponies (though circuses do still have ponies and horses that do tricks), and so we don't really have much call to cast aspersions on actual circus ponies that lack versatility, and so the figurative use is now much more common than the literal, but the literal sense is the origin of the figurative, and it really is as simple as being a pony that knows one, but only one, trick.