Hi!
I hope you guys can help find this book. I read it in the mid-late 80s, somewhere between about 4th and 8th grade. I don’t recall any illustrations. It was set in a mythological land and was about a kid who rode across the desert on the back of a large crab. I think there was a procession of crabs, migrating maybe. I think the kid’s people had never been across the desert and didn’t know what existed on the other side. And maybe he had to eat the crab (or one of them) to survive. He makes it across and there’s another civilization across the desert, I think.

Thanks!