There was a specific type of Beholder that I used as a shapechange target in 3.5, but I can't remember exactly what it was called, or its specific abilities. What I remember is that it wasn't a floating ball, more like a pillar with eyes sticking out. I believe that it had some kind of ability to freeze things in time, and I believe a dominate person eye ray? It was definitely high-CR, but had few enough hit dice to fall under the limit for shapechange. Possibly the highest-CR Beholder. I believe it was in one of the later books, could be Lords of Madness but also might be in the MM3 or MM4.
What specific monster is this?