It used to be that Graham called super heroes "super models." I'm not sure why--I can't think how he would even know that phrase. But anyway, for a while, seeing a picture of the Avengers or Superman would prompt Graham to point and say excitedly, "Super Model!" Close enough.
Now he calls them "super zeros." More to the point, he likes to be the super zero. Being Super Zero involves wearing costumes (preferably with masks), racing around the house (often with Matthew), and yelling "to the rekue!" at the top of his lungs, which makes Dave and me shake our heads over the intensity of the cuteness.
Here are some pictures of our Super Zero.
To the rekue!!!