Circle opening
that's a square
Ware Opening: Promotion Gambit
Why it works: 500 elo players will try to let their rook out but if you don't do anything with the pawn they will continue to push.
The Queenless Gambit (declined, f6 instead of Nf6 makes it the kick variation of the Queenless Gambit)
The Queenless Gambit (extra trading variant, not moving the dark squared bishop after Be7 is the semi-declined variant)
Example: The modern opening