Zygarde Cell may be based on cells as well as single-celled organisms such as flatworms (specifically planaria), slime molds and members of Euglena. Some planarians' ocelli also resemble eyes, which may have inspired the designs for the Cell and Core Zygarde. The hexagons within them may represent a cell nucleus. Possessing 100% of its total cells, Zygarde Complete Forme is said to exceed both Xerneas and Yveltal in power.
Zygarde Cores are capable of absorbing sunlight to regain their strength and can speak telepathically. Zygarde Cores are a multi-cellular organism, which have their own will and are sometimes able to act on their own, while the Cells form the rest of Zygarde's body and are only able to act on the Core's orders. Zygarde Complete Forme contains separate Cores for each of its wings and its tail. In this case, each Core can make decisions and act independently of the others
Zygarde 10% Forme has a relatively small canine body. It is primarily black with a green collar and a leash-like extension on its neck. Additional green markings include: two hexagon markings on its chest, a small hexagon over each eye, the area around its mouth, and its front left paw. Zygarde 10% Forme may be based on Fenrir. The green leash-like object around its neck could be based on Gleipnir, the rope that binds Fenrir.
Zygarde 50% Forme has a serpentine body with green and black markings. Most of its back, head, and neck are black, while the underbelly and the tip of its tail are green. Its eyes are made of four green hexagons, similar to an insect with compound eyes, and there is a thin, white line down the center of its face. Zygarde 50% Forme's appearance is based on a serpent in the shape of the letter Z. It may also draw inspiration from Jörmungandr, a sea serpent that encircles the earth, and Níðhöggr, a dragon that gnaws at the roots of Yggdrasill, the world tree.
Zygarde Complete Forme has a large, humanoid body with a long tail similar to Zygarde 50% Forme's body. There are several flat protrusions around its head and triangular protrusions around its neck. These protrusions create a crown-shape. Zygarde Complete Forme may be based on Hel, the ruler of Helheim, the realm of the dead in Nordic myth. The colors on Complete Forme's chest match the colors of the real-world flag of France, the country which inspired the region of Kalos.