The unnamed Brunette Vampiress (Mishel Prada) is the villainess from a Diesel Jeans commercial released in 2009.
The ad shows the woman engaging in a passionate encounter with her unnamed date, which leads to the pair getting into bed together. The woman undresses her date, but he stops her from removing his jeans. Her constant attempts to take off his jeans lead to the woman flashing her fangs and revealing herself as an evil vampiress. However, the man is actually a vampire hunter, and he anticipated the villainess revealing her true nature.
He later reversed her and pinned the villainous femme fatale down on the bed and killed her with a wooden stake, while taking her fangs as a trophy of sorts.