Teenage Mutant Ninja Turtles (1989)

Don't Fight Bebop
Go to the end of the 2nd sewer on the first map where Bebop is. Wait for the last batch of flies to pass by. Jump over the mini pillar. A single fly should fly over your head and into the area where Bebop is. Let the fly alone do not kill it. When you get to the end of the sewer, you won't have to fight.