bob: explodes you.
create the most stupid chess pieces!
Pown. Starts in the corner (a1/a8) and has to move one square diagonally each turn until it's reached the opposite corner where it promotes to a pown of the opposite colour. Only then can you start moving other pieces. Powns can move through other pieces that are in the way but they can't capture.
Nokynuke. It occupies the whole center. Each of the squares have to be occupied. Not necessarily at the same time. And it creates an IMPLOSION, absorbing the board.
The Transformer: starts as a pawn but turns into a different piece every turn. If it is checkmated as a king, you lose the game.
The zombie bishop: moves like a bishop but if it captures a piece that piece does not leave the board but instead returns to its starting square. If a piece is on that square it is captured. If the zombie bishop itself is captured, the piece also captures the capturing piece.

Robometal. Moves like an Amazon. Can throw nearby pieces. Also, launches missiles and throws lasers. Needs to be captured 3 times unless the piece is godly.