Invent the new worst/most useless chess piece ever!
The Dummy. It cannot be captured and cannot move to any square other than the square it is on and can skip a move by jumping on the same square and can exchane squares with certain special pieces.
The pinyy it can kill only your pieces and placed besides the queen. If any of your opponents pieces capture it the will become immortal and the guest will come
Is the king not useless enough? If that’s the case, make a prince to replace it. The prince is unable to move independently but moves each time when another piece moves, going on the square it was on before.
The idiot: It affects a 3x3 area by making its own color pieces disappear. It only affects your pieces.
The black hole. It swallows everything including the board before the first move is made.
Credit to @Luvrug for inspiration
The Queen inverter: When your queen checkmates the enemy king the sides switch and you lose the game.
The king's servant. It follows the king and occupies 1 square. Completely useless, disturbs other pieces and slows down the developement also prohibiting the kingside castling. It can't take but it can be taken
The SNEAKY SNAKE: It is a spirit that migrates randomly from piece to piece each move. If it catches you looking away from the board, it will move whatever piece it is in at the moment to a different square.. It magically changes the recorded score to support the new position so that no claim can be made against it.