My friend and I like picking a random asshole we see on the street and then just fucking with him or her for no reason. We like to break their car windows, vandalize their house, and whatever else we can think of. What else could we do to drive this random douchebag crazy?
You could dress up as superheroes and scare the shit out of this person. Put some fake blood and scary makeup on and jump out from some hidden place screaming and shouting "save us from this nightmare!" Or make a fake emergency situation and call this person from a fake number pretending that your friend is in distress somewhere and needs their help. Have some dramatic music playing in the background and make them work on figuring out the situation while you record the entire thing.
Start sending this random douchebag anonymous gifts, like flowers and chocolates. If you're feeling really creative you could also sign the presents with humiliating messages, like "you really need a confidence boost" or "I hope this helps your self-esteem".  That way the douchebag will begin to wonder if they're being targeted by a stalker, which could really mess with their head.
You could dress up as superheroes and scare the shit out of this person. Put some fake blood and scary makeup on and jump out from some hidden place screaming and shouting "save us from this nightmare!" Or make a fake emergency situation and call this person from a fake number pretending that your friend is in distress somewhere and needs their help. Have some dramatic music playing in the background and make them work on figuring out the situation while you record the entire thing.
Start sending this random douchebag anonymous gifts, like flowers and chocolates. If you're feeling really creative you could also sign the presents with humiliating messages, like "you really need a confidence boost" or "I hope this helps your self-esteem".  That way the douchebag will begin to wonder if they're being targeted by a stalker, which could really mess with their head.