A slang originated in the Bahamas and commonly used to express amazement or surprise. In fact it can be used to express any strong feeling. It is not limited. Usually accompanied with the word "well" in front of it.
It was made by the legend himself MythyMoo.
He used this amazing line when he was playing G-Mod.
He described a beautifully burned corpse as a "Crispy Muthafucka"