It's one of the slime molds, of which there are many kinds. Not a mold, nor a fungus, but an unrelated organism. Harmless, they move along feeding on bacteria and small bits of organic matter. They can find those food supplies on almost any outdoor surface.

Slime 'molds' aren't toxic. Many living creatures feed on them.

Thank you so much! That explains everything :) I'm relieved they're not harmful.

We wintered some plants in our mud room, but it got warm early this year and some were coming out of dormancy. We brought some pots outside to water them, and I found several interesting things on them.

White fuzz?

Some things look like a bunch of white strings. Some kind of mold or web?

This really does look like a spiderweb. I have no idea what the specks in them are, dust or eggs or? I haven't seen any obvious bugs in there.

Not exacty fuzzy, looks like a clump of white balls.

Bad for plants/animals? Harmless? Something that will go away once they're outdoors for a while, or here to stay? Any help is appreciated.