I went to check what titles I had unlocked when I noticed that I have the Massive Family title. I certainly haven't had 20 pets, so I'm not sure why I have it. I could possibly have gotten it several years ago, if the requrements have ever been different, but I doubt it. How did this happen? :o

I have the same problem, but with a different title:

I checked my forum titles, and I have the "room for one" title, even though I had more than one pet when it was introduced, and have never had just one pet since then.... the achievement is showing as red (correctly), but the forum title is available in the options for me to choose

I have the opposite problem. That achievement has never had any counter for me, it's always said 0/20 despite the fact I have 12 pets. I know it's not that big of a deal since I haven't earned it yet but it makes me skeptical if I would even receive the achievement if I reached 20 pets since it doesn't seem to be counting.

It works, it shows 12/20 for me now