1. A close cousin to the shocker, the cobra consists of 4 in the pink, 1 in the stink. Simply form your hand into the shape of a snake head. The '4' will be your fingers, and ram your thumb up her ass.
2. Fun thing to do to drunk girls during hook ups and casual sex.
3. Easy way to piss off the girlfriend/wife if she isn't expecting it.
"Hey Matt, what's the matter with Kacey?"
"Oh, me and Vaughan ran a Cobra Train on her last night, she's just a little sore."