After all the years I’ve been playing, I‘ve tried all the cliches. But now, I tend to design more unusual concepts.
So I haven’t had it happen accidentally*, but I’ve been party to doing it deliberately.
As In, another player and I were talking about what we’d like to play in an upcoming GURPS game, and we had semi-related ideas. So we decided to go whole hog, and designed identical twin sorceress/warriors from a Barbarian tribe.
Had a blast.
* There was one 2Ed D&D campaign in which we used the Players’ Option books. Another player and I both designed characters that melded fighter, clerical, and magic-user elements, but in radically different ways. Before we even rolled dice, the other player complained about my “Superman”. His whining annoyed me enough that I shredded my character up in his face- NOT my proudest moment- and rolled up a vanilla PHB Thief in a few minutes.
Months later, I ran that same “Superman” character in another campaign involving some of the same players (but not the complainer)...and he was one-shotted by a greatsword-wielding skeleton who rolled a nat20. Those players who had been in that prior campaign openly wondered what the earlier fuss had been about.