What are some of the weirdest/scariest/most disturbing glitches you've had?

I keep warning you guys about the dangers of feeding your sims from the ITF synthesizers instead of real food, letting them keep making drinks using unfiltered municipal tap water, and playing around with radioactive gems with no forms of protection. The long term safety and effects of these things have never been fully established. After a few generations, things like this are just bound to happen. >:)