I'm a black mamba. Apparently these are the traits:
"Like most snakes, black mambas can be associated with great wisdom and a sharp mind. Snakes are powerful symbols, and those whose patronus takes the form of a serpent tend to also be powerful people in kind. The black mamba is unique in that it only forms for those who show a special kind of mind. Though gentle friends and purveyors of entertainments of the mental sort, black mambas are cunning, patient individuals that can hold onto grudges for a very long time if wronged. While they tend to be quiet, sometimes even shy, and not be wont to impose, it doesn’t meant that they can’t get things done. When applied correctly, a black mamba has the potential to a master planner, calculating and observant, willing to stay close to even their rivals if it means achieving what they’re trying to do."
I dunno, it's kind of accurate? I'm quite the opposite of quiet tho lol.