Way ahead of you on that. I scoured the Piazza thread when you first mentioned the zombie beholder, spotted the mention of African beholders and checked Dragon 215.
There isn't a stat block for an African beholder there, instead, it is mentioned only that African beholders have the same variant abilities as Nyame's avatar, and those variations are described. That's enough for the African beholder to get added to the index, but not quite enough to make the cut for a listing as an unconverted creature. (There is enough info there to make a conversion possible, but in cataloguing the unconverted creatures from Dragon, I haven't usually included minor variations.)
The variant stats provided in the article are actually for Nyame's avatar, with a note that those stats are also applicable to African beholders.I don't have that Dragon. Are the African Beholders supposed to be Nyame worshipers (or servants of Nyame)? If they have a strong tie-in to a non-beholder god, that could make them an interesting addition to a game that features beholders.
A few hundred, would be my estimate. Possibly several hundred, depending on how generously you want to count variations. Most of the variations were captured in the index, but I'm sure there are plenty that I missed or just didn't seem significant enough to warrant indexing.Off the top of your head, how many minor variations do you think exist? Is it in the dozens, hundreds or thousands?