Large Arboreal Lizards?

Well it does depend what you call large. The first thing that springs to mind, although it is not as big as an iggy, so you may not cl it as such, is a frilled dragon, my favourite lizard. I have known the very odd aggressive one but on the whole they are wonderful, I bred them for a few years and do find that they make good pets and are really quite amusing when they run across the floor on their hind legs.