Great Chao King

The Great Chao King or simply Chaos (カオス Kaosu) is an immortal, god-like creature composed entirely of concentrated, water-like chaos energy.

Chaos 0
Chaos was originally a normal Chao, but prolonged exposure to the energy of the Master Emerald caused it to mutate into a strange water-like creature. As Chaos 0, Chaos was made of water-like chaos energy from the Chaos Emeralds, has longer limbs, three fingers on each arm and two toes on each foot. It's head has three tips mimicking hair and the brain was in the center of the head and it's eyes were lemon-like.

Chaos 1
After Chaos absorbs one Chaos Emerald, Chaos has slightly changed. Chaos 1 increases in size and gains a line of "bones" that travel down its right arm into its hand, where the Emerald is located. As such the arm becomes bulkier.

Chaos 2
After absorbing the two Chaos Emeralds, Chaos 2 is taller and more muscular.

Chaos 4
After absorbing the four Chaos Emeralds, Chaos 4 is a shark-like water creature that can swim and dive into water.

Chaos 6
After absorbing the six Chaos Emeralds, Chaos 6 is no longer even vaguely humanoid, but a scorpion/spider/frog-like creature.

Perfect Chaos
After absorbing the seven Chaos Emeralds, Chaos will become a giant serpentine dragon-like beast with a mouth extending far beyond its eyes, which for the first time have pupils that resemble a reptile's. Perfect Chaos is a several-stories-tall monster composed entirely of pure chaos energy in liquid form. It possesses a large mouth with green razor-sharp teeth and a green tongue that extends far beyond its eyes, which are green and have slit-like pupils. It also has flaps of skin hanging from just behind its eyes, green horns on its nose area and behind its eyes, and a "fin" on top of its head containing its organic brain. Also, running from the base of its body to its back spikes and brain are green-glowing arteries. The base of its snake-like body ends in a flood of liquid with several liquid-composed tentacles extending from it.