Yawn

First appearance: Resident Evil 1

Information

This poisonous snake, bred for use as a B.O.W. test subject, escaped from the facility and was infected with the virus, causing it to grow to gigantic size. It appears to be yawning as it swallows its prey whole, and thus it was named Yawn by the researchers.

It's unique in that its width is inconsistent with its length, and the venom it secretes through its sharp fangs requires an unusually powerful serum to counteract it. If a victim isn't given prompt treatment, the venom will spread and incapacitate them within minutes. The Yawn does not have highly developed intelligence and is incapable of any physical movement beyond that of a normal snake.