Ink CubeThis can be viewed as the creators puzzle "Time Machine" reduced to one side.
Jagged CubeA cheap piece shuffle from the 1980s. Produced in Taiwan.
JT-BallA combination of the tricylinder 3x3x3, cornerless cube and an unusual stickering scheme.
Jugo FlowerA very rare puzzle in the tradition of "Lights Out".
Jumble IntersectTwo 2x2x2s (rotated with respect each other) fused into one puzzle.
Jumble PebbleA jumbling only puzzle with a strange yet unnamed geometry. It resembles the jumble rock.
Jumble RockA jumbling puzzle built around an unusual, currently unnamed shape.
JumblixA puzzle with the axis system of a face-turning pentagonal dipyramid. Ten of 12 possible moves only jumbling.
Junior Cross CubesA fully functional lower-order cross cube made with four Rubik's 2x2x2s.
K-CubeA self-made 2x2x3 with extensions.