Oh, I see. Sorry I misread your post. No, I think you only get those two options. Like you, I never use Cloud of Poison or the spitting one (I forget the name).
One good thing about Glot's Armor is that no matter how much hits the enemy does in one go (e.g. a stack of 200 Fire Spiders which lands over 1500 damage in one attack) Glot's Armor will absorb it and then die. So Glot's Armor is essentially 'at least one free hit.' This can be very useful.
