Here's yet another specimen I picked up at Home Depot recently. I know absolutely nothing about Adromischus cristatus, but I couldn't resist the wavy-edged leaves. I've never seen anything like it before. The common name, Key Lime Pie refer to the crinkled-edge of pie crust. Another common name is Crinkle-leaf plant or Pie Crust plant.
You can't see them very well in this photo, but there do appear to be some form of spines of fine hairs near the center of the rosette.
And here's the info on the tag.