Now I do! (I googled around a bit to try to verify that this is accurate. Seems to be? As a long-time Trek fan, I’m ashamed of my ignorance. )
https://en.m.wikipedia.org/wiki/Mary_Sue
https://en.m.wikipedia.org/wiki/Mary_Sue
I am particularly partial to Overly Sarcastic Productions' take on Mary Sue:
https://www.youtube.com/watch?v=H2-GIY9RTqU