Anybody chew tobacco in your house? Got any weird birds.
Something the cat brought in? An angry booger???

Haha no tobacco, no birds, no cats. Maybe some boogers but not this variety. Any ideas anyone??

Possibly a specie of wood mold given the tendrils which appear at the edge of the body. Generally feeds on rotting wood but it doesn't appear the wood if it's wood is rotting that it is growing on. If you haven't remove the clump and spray some bleach or wipe it on the area to kill any remaining tissue and spores.

Scott

Thanks, Scott. Any idea how it would have started growing there in the first place? Hard to imagine that spot on the window (especially indoors) would be typically very conducive for it to grow.

Spores are everywhere. For some reason this one found the window sill a friendly site to set up shop. Any condensation on the inside of the window? If so that might be what encouraged it to settle down and homestead. If not then....perhaps a space spore from Mars?

We do get some condensation early in the morning when it's really cold.

I removed the mold a couple of days ago and made sure to apply white distilled vinegar. As careful as I was I still made a little of a mess with the spores crumbling all over the place as I cleaned it up.