West Indian Slang (Patwa) used as an exclamation of surprise/shock. While it is a portmanteau, there is no right or wrong when it comes to which word gives the "s". Because of this, in the West Indies, it is never used to describe a person or object, only as an expletive exclamation.
Scunt!!! That 50,000 Volt shock hurt!
(Thanks to the guys from Ghana I work with for teaching me this, and many other, great patwa expressions).