Enter a clue or pattern or both:
Diller's "husband" (4 letter answer)
The answer FANG is uncommon, appearing about once every 375 puzzles.
Canine on a feline
One drawing blood
London's "White ___"
Part of a vampire
Point of attack?
Jack London's "White ___"
Part of the mouth of a cottonmouth
FANG as a noun:
1. a Bantu language spoken in Cameroon
2. canine tooth of a carnivorous animal; used to seize and tear its prey
3. hollow or grooved tooth of a venomous snake; used to inject its poison