Tiamat

Tiamat was the lawful evil dragon goddess of greed, queen of evil dragons and, for a time, a reluctant servant of the greater gods Bane and later Asmodeus. Tiamat was also the eternal rival of her brother Bahamut, ruler of the good metallic dragons.

Appearance

Tiamat was a unique chromatic dragon, who had one head for each primary color of the most common species of chromatics (black, blue, green, red, white). Each head was able to operate entirely independently of each other and had the powers of a member of the respective race of dragonkind.  Her body also had traits in common with a wyvern, including a long tail tipped with a poisonous stinger.
She also has a avatar The Dark Lady was a mulan woman with long dark hair and completely black eyes. She always wore dark robes and frequently had a seductive smile on her face.

Personality

Tiamat was arrogant, greedy, hateful, spiteful and vain. She never forgave any kind of slight and was focused on obtaining more power and wealth. She disdained mortals, regarding them as mere disposable tools in her schemes. When needed, she was charming and fey, but her self-serving and reptilian personality betrayed her sooner or later.

After having experienced relative mortality as an archfiend, she became less reckless but also paranoid.
Tiamat enjoyed the company of male dragons, and had many great wyrm consorts of the chromatic varieties.
She had an insatiable greed for treasures, but preferred that her followers brought it to her in the form of gifts instead of searching for riches on her own

Divine Symbols & Sigils

Dragon head with five claw marks

Divine Classification

Dark Goddess

Realm

Avernus

Church/Cult

Church of Tiamat