Derived from the infamous "Goatse ( http://www.urbandictionary.com/define.php?term=goatse )" interwebs phenomena. Can describe e.g. any kind of nasty dirt or liquid but as well any appalling things in general.
Can be used as verb ("goatsefy") as well—meaning: to fuck something (usually an object) up, to fuck it up bad!
Dude, your whole jacket is full of Goats'! Go, be ashamed of yourself!
Stop looking at my sisters ass! I'll goatsefy your Lambo, fucking shmo!