Divinity 2 How do you summons multiple creatures

When ever I summons an additional creature, my first creature disappears. How do I get two or more? In the skills preview it shows the hero summonsing a ghost and a demon.

And speaking of summons. When you summons the undead are you summonsing the creature you created in your Necro Lab?

I've never heard of any possibility to summon more than 1 creature.

You can only have 1 creature at the time. And no, "Summon undead" summons different creature than one you create.

Just got back from a biz trip so I haven't got a chance to test it yet but I finally discovered how to summons my creature in the necro lab. (click the little white sea shell looking thing in your inventory). I think using that in conjunction with my summons spell will allow me to have multiple creatures.