I've never run a game with a Beholder in it, although I guess I'm more than adequately equipped to do so now. I tend to reserve those rounded bases for more science fiction themed minis, but I think this guy could play in a variety of sandboxes, depending on the situation.
I do wonder what initial games with the Beholder must have been like, back in the days when the Greyhawk Supplement was just a twinkle in Robert Kuntz & Gary Gygax's eye, so to speak. (From my reading on the 'net, I gather that Kuntz's older brother Terry came up with the Beholder, and it caught Gygax's eye, again so to speak, as a good candidate to add to the monster roster.)
Beholders are very much a D&D monster, something more out of a pulp science fiction story than folklore or fairy tales. They feel almost like a pen & paper prototype for a video game sprite, a list of game effects with a cursory personality (they're mean and bad and want to kill you) and a thin veneer of monster colored paint wrapping the whole thing up.
Of course as 40+ years of D&D have passed they've been fleshed out and riffed upon. (They got a big boost to their backstory in Spelljammer, which I still have a fondness for, even though it could have been a lot better than it was.)
|If you're, like, 80% eyeball, do you really want to get within arm's reach of somebody with a dagger?|
I may sound like I'm being critical, but actually I kinda like how semi-abstract they are in earlier editions. They're a product of the rising creative tempo of the game, back when there weren't any boundaries on ideas and anything strange and memorable could take root.
So here's lookin' at you, Beholders.