Mercury

"You know, most vendors worth their calomel would demand an arm and a leg for this manner of goods... I'll be easier on you and only ask for one of the above~"

This serpentine creature's affably quirky exterior conceals a disturbed mind. Although she likes to call herself a medic, nobody in their right mind would trust Mercury with their health, the fact that she never actually went to medical school being the least of anyone's worries; yet there she is, always brandishing her arsenal of surgical and dentistry tools. Throughout history, she has lived as a medical charlatan, performing dangerous operations and selling her (usually ineffective and oftentimes poisonous) alchemical concoctions. As ridiculous as some of her "medicinal" creations were, she used to be able to maintain her trade with no trouble, due to her smooth talking, persuasion skills, and haggling talent, a con artist like no other. Now, only the most desperate will risk turning to her - but still not for medical attention, for as a savvy black market trader, she has access to goods beyond anyone's wildest imaginations. The price, though, is often just as high, and doesn't necessarily have to be expressed in ordinary currency either...

The annoying thing about Mercury is that, while sometimes she'll talk your ear off with her random nature facts and morbid stories and anecdotes, or trying to sell you something or another, you will inevitably end any chat with her knowing even less about her than before you started. She takes care not to reveal anything about herself, and for good reason - really, nobody is sure who or what Mercury is, the only certainty being that she is not human. This isn't hard to observe. She regularly throws the laws of logic, nature, and everything else out the window, able go up walls, stand on the ceiling, contort her body and extend her limbs unnaturally, slither under doors and through keyholes... Often, she's been observed producing objects seemingly from thin air, seen in multiple places at once, and strange, unexplainable events seem to happen more often around her. However she does have several weaknesses, including cold iron and even blood, sulfur, and salt, which significantly weaken her, making effective deterrents.