OK, probably not extraterrestrial, but it did pique your interest. :) After my dishwasher recently stopped working I learned that it has a small filter/strainer located just before the water inlet valve so I disconnected the water supply and found this slimy wormlike mass completely clogging the strainer. To put it in perspective, the dish in the photo is a roughly 12" diameter plastic dish that goes under a flowerpot. The smallest mass on the right side was in the filter itself. The long piece in the middle was bunched up immediately behind it, and together they (not surprisingly) completely cut off the water supply to the dishwasher. The piece on the left was still in the pipe or the supply hose coming from under the sink, and appeared a few minutes later when I ran the water into a bucket just to be sure the line was flushed clean. It looks "wormlike" although I'm pretty sure it's not actually a worm, but it was slimy and held together when lifted and moved about. As you can see the color varies from bluish to whitish to brownish. The water comes from our own well, and there's no way that this passed through the whole-house (AquaPure 5 micron) water filter, so whatever it is it formed inside the house in the water supply. I was initially thinking it was a bacterial or algal mass, but could it be some sort of aluminum hydroxide gel formed from water heater anode electrolysis? We drink the tap water all the time and nobody's experienced any hint of illness from it. The water pipes are a combination of the original copper and some more recent pex sections. Our water has a fairly high iron content but otherwise unexceptional. The only other possibly relevant thing I can think of is that years ago the water occasionally had a sulfur dioxide odor after we had been away and hadn't used it for a week or more but that hasn't happened in recent years (probably not since the last water heater replacement).