Thallium Dragons

Thallium Dragons are one of the nine Metallic Dragons of Drakomere. They are associated with the Tone of Domination, the Harmony of Manipulation, and the Melody of Arcane. They originated in Wild Plains, and are associated with the Origin Ancestry, the Humans. Due to their association with Manipulation Magic, they are also tied to the vice of Deceit, and the virtue of Humility, as well as a secondary tie to Ouroboros, even though Tiamat is their primary god, being god of Metallic Dragons, thus also being related to the sea.
Thallium Dragons are an outlier when it comes to the Metallic Dragons, they are fairly short-lived in draconic terms, sharing this trait with only Polonium and Aluminum Dragons. Their size is also out of the ordinary, they're the only Metallic Dragon to be under 3 feet at maximum size, however they use this to their advantage.They also generally prefer civil society surrounded by the non-draconic, over more free and small Dragon colonies.
They also tend to be quite malicious, working as assassins, using their small size to get in an out undetected. They have a dull silvery-green appearance, which also helps for camouflage, and their Breath is a toxic gas that, once affected, slowly kills a person over a few months, making it hard to narrow down where and when the poison was administered. They can also hyper concentrate their Breath, having it take begin to take affect within seconds, but this is rarely used due to the effort and energy it takes, as well as being far more obvious, and taking on a secondary trait of electric energy wrapping around the poison gas.
Thallium poisoning manifests first as stomach pain, diarrhea, and vomiting. Then later manifesting as tremors, headache, insomnia, seizures, lack of muscle control, nerve damage starting at the feet and going up, coma, and death. It also causes abrasions, hair loss, and reduced sweating.
Older Thallium Dragons tend to take on a bluish-gray appearance which is often seen as undesirable, but this coloration can be washed away with consistent oil-washing, expensive, but used as a status symbol. Because of the bad reputation a lot of Thallium Dragons possess, they are commonly seen as untrustworthy, but those who do take on more honest roles in society tend to become artisans, making medicines, glasses, tools.
Thallium Dragons also have fantastic eyesight, better than most birds of prey. Their eyes are stunningly beautiful as well, almost enchanting.