Yawn was a regular snake that was originally bred by Umbrella scientists as a Bio-Organic Weapon (B.O.W.). This specimen escaped captivity and escaped recature. When the T-Virus leaked throughout the Arklay Mountains, including the Spencer Estate and the Arklay Research Facility, Yawn was affected with it. The snake, overtime, grew in size and length and could easily devour a human in one bite.
During the events of the original Resident Evil, Yawn lurked about the mansion in search of prey. When the S.T.A.R.S. Bravo Team was sent to the mansion, Bravo members Richard Aiken and Rebecca Chambers encountered it. The snake attacked and cornered them and bit Richard when attempting to save Rebecca from it. The snake then retreated into the attic. S.T.A.R.S. Aplha Team members Jill Valetine and Chris Redfield later discovered Richard and Rebecca.
The gigantic snake was later fought in the attic but escaped death by escaping through the fireplace. Yawn was later encountered in the library where Chris and Jill killed it.
Resident Evil: Deadly SilenceEdit
- In Resident Evil, Yawn would devour the character character if he/she are at low health. In the GameCube remake (commonly referred to as the REmake), Yawn would wrap around the character and crush them in its coils.