In still water?

Naw, it's what's left of a shag carpet after kitties have had their way with it.

Annette

Skin knitting after a boo-boo?

...on a damp rock???

Nancy.

Why do I have the sudden impulse to play snakes and ladders now?

Sierra

Under the microscope?

Is it my bones knitting?

Janie

I like little dani's answer! But I'll say in pond water.

Thanks for the bonus trivia, TM

It's called Microdictyon umbilicatum, and it is a green algae that grows on coral reefs in the sea. I don't really know anything about it, I just thought it was a cool picture.

The picture is magnified 20x, which is probably why you all didn't recognize it. :-)

for Nell, Nancy, and Stagerat, who were close enough.

Gotta go. Grandsons are here today.

TM

Late to the party, I played along while catching up. Loved everyone's witty guesses!

Thanks Cyn, Janie and TM2!