I recently came across a horned melon (Cucumis metuliferus) in a grocery store. I've seen them before but after reading up about it, I wasn't sure if it was something I wanted to try. I didn't end up getting it. A while later Jame brought one home. Curiosity got the better of me and I ended up trying it.
I've got to say that I'm really not a fan. It tastes like an extremely acidic cucumber with harder seeds. Although fun to look at, it really wasn't fun to eat!
I still recommend trying it. Just go in with low expectations and you won't be disappointed. Then you can grow your own with the seeds. Apparently they're as easy as the related cucumber, and the melons could be fun decorations for fall.