Did you plant any yellow straight-necked summer squash?

Nope. That was my first suspicion - yellow summer crossed with something, but I only planted zukes this year for summer squash.

It kind of looks like a yellow summer, but such a deep orange, and very hard-shelled. Oh, and quite warty!

The old OP straightnecks are quite warty when mature and have this general appearance. When dry it will be hollow like an ornamental squash/gourd. Most likely a mixed breed tho.

Do you think I should try to eat it?

It would be harmless in any event. If it is a straightneck and it is dried, all you find is a hard rind and a clump of seeds. No meat like a winter squash.

It is a mongrel. It has happened to me many times. I have always eaten my mongrels. This year I had a zucchini turn into a bottle shaped gourd (I ate it, nothing special). Two years ago I had a winter squash, nominally a butternut, with butternut shape and Hubbard size and warty rind, which was one of the best tasting squashes I have ever had (I saved the seeds). I had to tie it to the trellis because it would have broken the vine. One other zucchini made a giant vine and is blooming only now. This has happened with both Territorial and Johnny seeds. With Territorial melon seeds I had a veritable house of ill repute, and numerous soapy tasting melons.

I'm sorry to hear that about Territorial seeds.