This one's easy!
You require the following:
4 cans beer. Any kind will do, but I figure a nice dark ale will add to the overall aroma.
5lbs Headcheese. Can be found at any deli, as seen below:
1lb cooked spaghetti noodles, in small chunks.
1 large tomato.
1 pickle.
blender.
Blend mixture slightly, you just want to break the headcheese, tomato and pickle apart enough so it looks like half-digested bits of food. Proceed to pour all over moron's car/sidewalk/front door.
When he heads out to work in the morning it will look like some poor chap had a few too many drinks and lost lunch and dinner all over his car/sidewalk/front door.
Nothing illegal, nothing dangerous, and I can guarantee you he's going to be PISSED and grossed out cleaning that sticky, stinky crap off of everywhere.