It appears to be a "weed". Melons and squash have large, thick, and wide cotylons [the first two "leaves"].

I does have thick, wide cotylons....you can see it on the 2nd photo just above the first true leaf.
That's why I thought it was something edible (barring research on edible weeds... smile).

I'm trying to decide whether or not to pull it or let it grow a little longer.

Deanna

That's no curcubit. That's a sunflower. I'd bet a whole dollar on it.

Looks more like a sunflower seedling to me if not just a weed of some sort. Definitely not a squash at all; those are quite distinctive, and a single typical squash (or pumpkin) leaf quickly follows the fat cotelydons. I found one photo of squash seedlings; see link below.

Here is a link that might be useful: Squash seedlings

Hmmm...interesting. I haven't grown sunflowers for several years (none in THIS compost pile unless delivered by birds).
I agree that it doesn't look like like any squash or melon I've ever grown before!!
Just very odd. There were several of these grouped together in the pile (you know, cold pile, dumped the seeds from some melon or something in it and it grows!...in a clump! LOL).

Just odd. I think I'll yank it since my space is somewhat limited and I didn't plan for squash...there...

Thanks!
Deanna

Quite possibly these seeds were gathered from a birdfeeder or something like that by some varmit and stashed in your compost. That happens to me all the time with the neighbors chicken feed.

Could be! We don't have a big "critter" problem, but who knows!
The mysteries of gardening!!
There's something new every year.

Deanna