a toilet seat.
The seat is likely old and fragile, and had occasion to crack after routine use last night. The crack was apparently deeper than you'd think from casually glancing at it. I saw the crack before I went to bed and used the toilet without incident or alarm.
Later, I woke up at 5am to pee, didn't turn the lights on, sat down, and subsequently woke Ivan and the cats with my screaming as the crack in the seat grabbed my thigh and pinched and for a moment, felt like it was not going to let go. The shock of the pain was quickly supplanted with the we'll laugh-about-this-one-day scenario of "How do I tell the emergency room doctor why I have a toilet seat clamped to my thigh?". I was able to free myself soon after. I bled mildly and have a laceration, but otherwise, no big deal.
However, this seems the perfect time to remind the uninitiated of P.J. O'Rourke's three rules of humor:
1) Toilets are funny.
2) Dead children are not funny.
3)...unless they were killed by a toilet.
be careful out there.