Invent the new worst/most useless chess piece ever!

The loser: You lose if you have the piece (and you always do at the start)

Mmm... sounds like a pretty good game xP

easily the "onedeadrabbit" piece.  it never gets on the board.  it just rolls around on the side kibbitzing and crying alot.

The Hamlet: determined by coin toss, one side gets the Hamlet king, unable to make a decision, if checked, it can't move or block and loses automatically.

a wall, can't move, blocks your own chess men.

There is a variant called "Wall Chess". Both players start with a wall that occupies a3-h3 for white and a6-h6 for black. It can't move.

The Chuck Norris. When Chuck Norris is in the game, he wins the game. You lose, your opponent loses, and everyone playing chess in a range of 100 km lose their game.

The goblin catapult. Sacrifice two pawns: destroy target pawn. Moves like a king, can't capture. Actually, it's not so bad.

The invisible hologram. White's is on e4, while Black's is on e5. It cannot move, capture, or be captured. Other pieces, regardless of the color, can move onto the square on which it resides.

The communist. It replaces your king, so you can't be checkmated. Every turn, you must remove one of your pieces from the board. You still have to do that until the end of the game, even if the communist is captured. If you run out of pieces, you lose the game, but some people will still believe that piece did good long after the game.

The troll. It prances around the board and trolls random pieces throughout the game. For example, if the player tires to move it to e4, it may move to b1 and convince the b1 knight that all the other white pieces are evil. Subsequently, the knight starts to attack the white king until White resigns.

The obnoxious spectator. White's obnoxious spectator resides on h3 and loudly insults and castigates the White player whenever he/she makes a move that is not recommended by Stockfish. It refuses to move, but can be captured. However, Black refrains from capturing this piece so that White continues to be discouraged. 

The communist (version 2) Replaces the king, all of your remaining pieces become pawns, at the beginning of every turn, remove a pawn from the game. Even though this side will lose the game, some of the pieces on the other side of the board will think that it's better to play like that and will be deaf to any contrary arguments.

the dragon: moves like a knight and cannot be captured.

The fanboy. You can't move this piece, but instead of moving it, you can pause the game to post on chess forums.

the bouncy pawn. You move it and it starts bouncing until you shout stop bouncy pawn

The modern artist: When this piece is on the board, you can't calculate any of your moves. And both sides win the game, as long as they are friends with the judge. If a player has a rating above 800, that player loses the game, because he plays in an obsolete way.

The Impressionist: makes board so fuzzy that both sides agree to have a drink of absinthe and not play at all.

The square. Can't move or capture, but other pieces can move over it. Each side starts with 32 of them. If the bottom right square is a black one, you are cursed forever.

The coffee break. All the pieces along the same rank and file of this piece cannot move . The piece itself is immune to capture from beginning to end.