Knight's Gambit
The king now cant castle and is in the open while also opening a diagonal for future checks, and it also cost just a single knight, because the king takes the knight the d4 pawn can be defended on the next move.
If the king doesnt take and moves the queen, you win a rook anyway even though the gambit is declined
Or if they are -1000 elo and goes "ooga booga i take d4 pawn" take their queen, show them no mercy.(jk)
Also according to google the earliest castle is 4 moves
If you think this is good, play the jerome gambit. The accepted variation of the gambit is bad for white. Black can always manually castle (Rf8, Kg8)
Chicago gambit