The Percheron. A superknight that captures everything in its L-shaped path. Purely because I'm quite a fan of those - any big powerful draft horse really - and I'd like a chess piece based on one.
The wooden chess piece should also have a thick neck with visible muscle bulges like an actual Percheron.
A piece that can't go to a specifical square, if it does, the piece's owner wins the game. it would move like a pawn but also diagonally, 1 square per move. It makes no sense but could be fun