A polyomino is a generalization of the domino to a collection of squares of equal size arranged with coincident sides. Polyominos were originally called "super-dominoes" by Gardner (1957). A polyomino with squares is known as an -polyomino or "-omino." Polyominoes may be conveniently represented and visualized in the Wolfram Language using ArrayMesh. Free polyominoes can be picked up and flipped,