Basically humor that involves changing a title of something and how it might go.

Was at my parents and my dad was watching a western movie then he switched over to CSI.

As soon as the music started I said, "Cowboy Scene Investigation!"

"We found this hombre riddled with arrows."
"Yuh figger the Injuns did it?"
"I'd like to test them at the lab afore I leap ta any conclusions."