Hanon in the English dub. He is from a race known as the Hellions, who come from the Protector clan. Anon can swallow and absorb people within himself, thus making their bodies his, as well as gaining whatever abilities they have such as Robert's power to make the ideal thing and his sacred treasures. With a surprisingly humble nature, he has a hard time understanding humans and tends to experiment on them with reckless curiosity. Although it appears that Margarette is his father it is actually a Hellion who swallowed Margarette using his appearance.
Later in the series, he swallows King of the Celestial World who is "God" and changes up the rules of round 4. He first told Ueki that his dream is to destroy everything, but in fact, his real dream is to have someone who can defeat him.(source : wikipedia)