Gaia

Gaia (ガイア), formerly known as the Chaos Dragon (混沌竜), is the pet dragon given to Milim by Veldanava.

Background
Veldanava used the last of his energy to gift his daughter a pet dragon, in the hopes that she wouldn't be lonely. After Milim became orphaned, the pet dragon remained her only close family, the two living a peaceful, uneventful life together. These times, however, didn't last long as they became the target of a certain elven kingdom led by Jahil. In her rage, Milim wiped out the kingdom for killing her friend and awakened as a True Demon Lord. The gifts from her Harvest Festival brought the corpse of her dear friend back to life, but because its spiritual and astral bodies were severely damaged, it was resurrected in a corrupt state. Influenced by Milim's rage, it became a force that transcended both good and evil. In her sadness, Milim sealed her former friend away to end its destruction.

Majin Behind the Scenes arc
The corrupted dragon was unsealed by Free Guild Grandmaster Yuuki Kagurazaka after discovering its location through the Guild's network. It was placed under Mariabell Rosso's control and further agitated under the influence of her Unique Skill Greed. It was then sent to eliminate Demon Lord Rimuru. Milim, who accompanied him in their exploration of the ancient ruins of Amrita, was shocked at the unexpected appearance of the dragon, and engaged it once more to prevent its rampage.

Overpowering it, Milim destroyed the dragon's spiritual and astral bodies, and its heart core was devoured by Rimuru. In a show of generosity to Milim, Rimuru patched its broken heart core and placed it in a Pseudo Soul. It was fused with a Master Core, creating an Avatar which would serve as its body, reviving in the shape of its choice.

Relationships
Milim Nava: Gaia's friend and master. After its rebirth, the two have rekindled their once intimate relationship and often play together, at the cost of Milim receiving a harsh scolding from Frey. Gaia's playmate when roaming the dungeon.

Rimuru Tempest: Gaia's playmate when roaming the dungeon.

Veldora Tempest: Gaia's playmate when roaming the dungeon.

Lamrys: Gaia's playmate when roaming the dungeon.

Abilities
Born with a strong affinity for the earth attribute, Gaia has the ability to manipulate gravity.

Chaotic Breath: A highly concentrated miasma that corrodes anything it touches.

Gravity Barrier: A barrier that dulls physical attacks.