Oakville Blobs
The residents of Oakville, Washington, a village of less than 600 people, noticed that the rain was not falling as it should have in the summer of 1994. On that particular day, the rain was goopy and heavy, resembling Jell-O splatters dropping from the sky. The rice grain-sized lumps were not large, but they did gather on the ground to form a jelly-like covering. Over the following few weeks, the same gloopy rain poured several more times in and around the Oakville region. Then it vanished.
Locals started to feel like they had the flu. A microbiologist examined the slime and found that although it contained lots of germs, the bugs weren't hazardous. Those who contracted it said that it led to a flu that, in some cases, lingered for several months.
Some others believe that the goo materialized on the ground rather than falling from the sky. Residents who were questioned for an Unsolved Mysteries episode reported it dropped, and one man even claimed to have been in his car at the time and struggle to get it off the windshield. The phenomenon hasn't been verified or explained yet.