I'll go first: https://www.chess.com/openings/Kings-Pawn-Opening-Barnes-Owen-Unicorn-Variation
Unless this is some meme I haven't heard before (there were 3 comments, so some people know about it) but I think most people have never heard about this one.
This isn't really a thing on explorer, but this is kinda funny.
White Lion.
Alekhine Defence, Mokele Mbembe variation.
I've actually heard of this one.
Vienna Game Frankenstein-Dracula variation.
I've heard of this one too. I know a lot of openings for some reason.
Birds opening, From, Bahr Gambit.
Bishops Opening, Boi, Stien Gambit.
Bishops Opening, Calabrese Countergambit.
Kings Gambit Declined, Falkabeer, Hinrichsen Gambit.
French Defense, Three Pawn, Sanky-George Gambit.
Scandinavian Defense, Closed, Dougherty Gambit.
Center Game Accepted, van der Lasa Gambit.
Sicillian Defense, Brussels Gambit.
Coca Kola Gambit.
Medusa Gambit.
Saint George Defense.
Polish Opening, German Defense.
Three Knights Game, Winawer Defense
Kings Gambit Accepted, Gama Gambit.
Ware Opening, Ware Gambit.
Sicillian Defense, Bowlder Attack.
Sicillian Defense, King Davids Variation.
Indian Game, Omega Gambit.
French Defense, Perseus Gambit.
Not something like "Halloween Gambit," Which is uncommon but most have heard before. I want really REALLY strange ones.