Case Cube (Cuboid)Elongated Fisher Cube made by Jean-Claude Constantin and rebuilt by Tony Fisher.
Cheese BlockA prism with 3 layers, 14 segments and the shape of a cuboid.
ChopsticksA mass produced 1x2x9 produced for Mefferts Jade Club
Christmas DominoA cheap taiwanese Domino with two christmas based motives on its two sides
Circle 1x2x3A 1x2x3 with circles in the small faces. This doesn't change the puzzle but looks fascinating.
ContainerThe Container is a Skewb mod produced by Tony Fisher.
Crazy 2x2x4A 2x2x4 with circles on the not-extended sides.
Crazy 2x3x3A 3x3x4 with two layers removed but not hidden.
Curvy ChopThe concept of the Helichop cube applied to a Curvy Copter.