A motorcyclist who chooses to "harass" other motorists by riding recklessly, doing stoppies and wheelies on heavily travelled roads, and riding way too fast for the conditions. The rider rarely wears any protection other than a helmet (where required). This is done simply to show off and has great potential to result in a dead, or temporary, motorcyclist. See also squid
Now that the weather is good, there are temporary assholes riding wheelies all over the place.