The event which leads to gaining a Fanny snake.
It is where the snake gains entry into a woman's (in some cases gorrila's) vagina. This is mainly caused by the snake being lured by the smell that drifts from the ovaries.
"Oh dear Mrs.X, it appears that you've got an egg in your uterus. Been doing a bit of Meat-Flaps Snake Charming have you?"
An unfortunate condition caused by women wiping their arses from the rear towards the vagina, typically resulting in fecal matter being smeared in and around the labias.
When I went down on that skank she had a serious dose of scat flaps. The smell made me barf all over her rotten pussy. Seriously if I was in to that kind of shit I'd have fucked a guy instead.