Fiddler Crab 

Refers to a man who masturbates exclusively and excessively with only one hand giving him an overly muscled forearm and bicep on only one side.

I could tell that fiddler crab was right handed because one arm looked like Mike Tyson and the other like Steve Urkell.

Fiddler Crab by Beaver Nibbler July 7, 2011

fiddler crab 

The fiddler crab is an extension of the shocker. Once you are successfully in the shocker position, quickly move your thumb up and down on the woman's clit to help stimulate the sexual experience.

Give her the shocker and make her cum with the fiddler crab!

fiddler crab by Shane Ryale August 20, 2007