There is a Phsyco mission called: Everyone Loves Slappy. Its in the Palisades Mall.

You will have to examine Slappy's dead Girlfriend (Slappy is the mascot of the mall).

Slappy will go crazy and try to kill you with a Homemade Flamethrower (Water Gun and Motor oil). He will also ride on rollerskates.

Jump out of his way and avoid the deadly Flames. He will eventually ride into a wall and he will be stuck against it.

That's when you whack the crap out of him. He will be forced to reverse then you run!

You can kill him this way. I recommend the following weapons for Slappy: Light Sword, Knive Gloves, Machete/Push Broom. A Spike Bat can also work well. Take some Food and Drinks with you too.