quick ultra boy question

I'm working on a picture of him and I was trying to make the green
thing on his chest. And then I realize I have no idea what that's
supposed to be. Anyone know what that shape is? I thought it was a
bird, but then in the waid-kitson run it looked more T shaped so I
have no idea. Also, i don't knwo what a bird has to do with him. Do
they ever explain what that is?

Thanks for the help, guys!