The square: gets trampled by other pieces and stays at its place. There are 64
Invent the new worst/most useless chess piece ever!

Worst? Confined to the context of chess, the worst possible piece (for the player of its own color) would be one which causes immediate loss automatically. Not confined to 'worst' in a chess sense, it would probably be a piece made of antimatter.*
Most useless? A piece with literally no utility, negative or positive... call it the DITG (for Dragon In The Garage). It's invisible, inaudible, incorporeal, etc. Heck, it's even unfalsifiable, as you can't prove or disprove its existence! Who knows, you could be playing with it every game (although the probability of that is quite low).
*My physics knowledge is not up to par, so correct me if I'm wrong. Is there a more destructive possibility? A piece dense enough to create a singularity, perhaps?

Worst? Confined to the context of chess, the worst possible piece (for the player of its own color) would be one which causes immediate loss automatically. Not confined to 'worst' in a chess sense, it would probably be a piece made of antimatter.*
Most useless? A piece with literally no utility, negative or positive... call it the DITG (for Dragon In The Garage). It's invisible, inaudible, incorporeal, etc. Heck, it's even unfalsifiable, as you can't prove or disprove its existence! Who knows, you could be playing with it every game (although the probability of that is quite low).
*My physics knowledge is not up to par, so correct me if I'm wrong. Is there a more destructive possibility? A piece dense enough to create a singularity, perhaps?
#ChessEinstein
#ChessCopernicus
The tax collector. it remains on e4 square and makes you pay 9.99$ per turn if you occupy this square with one of your pieces


A piece looking like R2D2, is only allowed to move when the king is getting checked and then only diagonal in a L-Shape

The Quing. This piece combines the movements of the queen and the king, but cannot move any number of spaces, nor one square in any direction; it must move the same number of squares as the opponent made on his last move if it has any legal moves; if it has no legal moves, you must pass your turn and say the word, "Quing!"

The MacPherson as a queen replacement.
Looks gorgeous and can move in any direction but limited to only one field of moving.

The Quing. This piece combines the movements of the queen and the king, but cannot move any number of spaces, nor one square in any direction; it must move the same number of squares as the opponent made on his last move if it has any legal moves; if it has no legal moves, you must pass your turn and say the word, "Quing!"
Reminds me of how the mime works in the game final fantasy tactics.
How about the invisible piece. It changes its position after each move but the thing is no one knows where it is because it is not visible. It cannot be seen, it cannot capture other pieces and you can place your own pieces on its square and your opponent can also place his pieces on its square. I call it "The Invisible Man."