Apologies for bumping an old thread, but this has been playing on my mind a lot lately.
I know that Beholder is a trademark of Wizards, but I've seen them in plenty of other games, just with different names. Just today I was playing Dragon's Crown on my Vita and came across a Gazer (http://dragons-crown.wikia.com/wiki/Gazer) - a Beholder in literally everything but name. Dragon's Dogma also has one, except it's called an Evil Eye (http://dragonsdogma.wikia.com/wiki/Evil_Eye)
The argument has always been that they are a trademarked monster, but if these guys can use them, why can't Paizo? What would be the difference if you just called them Gazers or something?