Women who remain single past 31.
Toxic Bachelorettes come in all shapes, sizes, and socioeconomic backgrounds, but share a common trait of wasting their prime mating years in a futile relationship with a guy they chose for the wrong reasons. (E.g., "I only date someone who uses colorful toothpaste, or answers his phone with 'Ciao'.")
Most of these toxic bachelorettes are fueled by pre-menopausal hormonal imbalances, and hate men in their age-group while constantly seeking affection from far younger men.
Ann Coulter is a toxic bachelorette according to Wikipedia.