Zygarde

Zygarde is a Dragon/Ground Type Pokémon introduced in Generation VI. It is a Legendary Pokémon that resides deep within the Kalos Region.

Forms

 * Cell: A flat cell that comes in many. They all form each Zygarde, depending on how many the Core can gather.
 * Core: The brain of Zygarde. The Core is responsible for gathering the appropriate amount of cells to ensure that Zygarde can take on the right form.
 * 10%: A form that takes on the appearance of a dog. It is said to travel extremely fast and has a powerful bite.
 * 50%: The default form only usable in both X/Y and ORAS. It primarily has Aura Break as it's Ability, which reverses the effects of Xerneas and Yveltal's Abilities that boosts the power of their respective Fairy and Dark Type attacks.
 * 100%: Also known as "Zygarde Complete", it is the ultimate form that Zygarde can take on in battle.

Origin
Zygarde (In it's 50% form) may have drawn influence from Níðhöggr, a legendary serpent in Norse mythology who is said to gnaw at the roots of the world tree "Yggdrasill".

Zygarde's 10%, 50%, and 100% forms could also be influenced by Fenrir, Jörmungandr, and Hel respectively. Those three deities are all said to be the children of Loki and Angrboða.

Reception
Zygarde received rather mixed reception initially, but like the third member of each Legendary Trio per generation, it gives the fans many ways to speculate what it might be capable of in future games. A lot of people are rather disappointed by it's lack of viability, despite having one of the highest physical Defense stats of all Dragon Types.

Some fans are rather disappointed to not receive a third version or installment to X/Y, which would have concluded Kalos' arc, as well as giving Zygarde an entirely new way to battle, just like Giratina and Kyurem did in previous generations.

However, many have rejoiced that all three of Zygarde's usable battle forms have now been confirmed to appear in Pokémon Sun & Moon.

Fans have also grown fond of it's 100% form, which takes on a much more powerful appearance. Some even enjoy the 10% form for it's dog-like appearance.