The thing looks like a failed fruit. I get them on Epiphyllums, sometimes on Gymnocalyciums. The ones on the jungle cacti often shrivel and drop, but the ones on the desert cacti seem to be content to just exist. I had one on a G. mihanovichii for 2 years before I accidentally knocked it off.

That's weird! Thanks. It's a pretty creepy looking thing.

Thats really cool, any possibility for a close up shot?

I'll take one next weekend. I'm back in Massachusetts now. It might be some kind of a mutant pup.

It would have to be mutant, because I have never seen Parodia buiningii make an offset.

Who knew cacti got acne? ;-)

Lol Seed!

I know these plants rarely offset and if they do, they would near the bottom. Whatever it is, it appears to be albino anyway. It kind of looks like an eye. Ewww