I saw quite a few of these oddly shaped things. My guess would be that they are the oothecae (egg masses) of a praying mantis. I’ve read that each species of praying mantis has a distinctive looking ootheca. After quite a bit of searching, I’ve been unable to find one that looks quite like this.
This one was on some sort of succulent plant, but I found others on tree trunks and various other plants.