The "block" and "boat" do not change, the "blinker" and "toad" have 2 looks that repeat, and the "glider" and "lightweight spaceship" ("LWSS") are spaceships which keep moving across the cells in each level. The "pulsar" is the most common repeat that has 3 parts. Most of the repeating patterns have 2 parts, like the blinker and toad. .