The Legless Pervert

Listen, you absolute buffoon. You probably think a pervert with no legs is just a sad person. But, this is a joke. A 'creepy crawly' is a play on words. It sounds like someone is crawling but also means the pervert is creepy. It's funny because it's unexpected and it connects the 'legless' state with a creepy nature, which is a common stereotype for a pervert. Get it? Probably not.