Cute, cheap edging

I am looking to make some cute edging, about 5 or 6 inches tall. I was thinking maybe of concrete casting, don't have a form, though, and want something cute. So maybe not that...

Anyone have any ideas? I would need a lot, but can work on my project a little at a time. What do you have as an alternative to the red or gray concrete scallopy things?

And I have dogs, so nothing sharp.