What's the most unusual thing you've found in a porta potty?

I found a complete set of car keys with a remote fob and a gym membership tag, sitting dry on the seat of a standard unit at a residential renovation site. It wasn't in the holding tank, just left behind. The homeowner had been frantically searching for them for two days. Turns out his toddler had a habit of tossing things in there when the door was left unlocked. The service visit that week was just a routine pump and clean, so I handed them over dry and intact. No cake, but it saved someone a locksmith bill. For events, the guideline is about one unit per 50 to 75 people for a four-hour event, but you always add more for alcohol or longer durations, fewer people per unit means less chance of odd stuff ending up inside. Weekly service is the norm, but high-traffic sites like festivals need daily pumping to keep up.