Great Yiffing

Yiffing
Yiffing is what happens when a Furry is exposed to certain stimuli (most notably Unobyiffium). They lose control of their bodily functions and let out a high pitched squeel that sounds like they are saying the word 'Yiff' (hence how the action earnt the name 'Yiffing') and release a large amount of bodily fluids in an extremely pleasureable way.

Many Furries become adicted to the feeling of a Yiff after experiencing it, as no other feeling comes close to bringing such sensations of pleasure for them.

A Great Yiffing
A Great Yiffing is an incident that occures when a large number of Furries gather together and are exposed to Unobyiffium.

The collective Yiff of dozens or even hundreds of Furries is enough to destroy cities, countries, even worlds.

This Great Yiffing need not take place in a single instance, but over a period of time. It is the act of destroying worlds through Yiffing, a deed that has occured several times across the galaxy, but most recently on the Planet 'Pu'.