So my son has become obsessed with the PBS TV show Super Why as of late, so we settled on Super Why as his costume. Super Why (Whyatt) is the main character on the show, he has the power to read. You can read more about the show here,
http://en.wikipedia.org/wiki/Super_why, if you want.
Here's a picture of Super Why from the show.

I also wanted to mention, I looked online to see if they had premade costumes, I figured if I could find one for like $10 I would just do that. Well, the costumes are apparently hard to find (even harder in his size) and they were going for $80 on eBay.

And now onto my little guy and the exhausting explanation of his costume.
The entire costume is made out of tshirts and one onesie (my serger was my best friend for this project). They were the only ones I could find in the colors I wanted to use, and they were toddler sized, so I had to use more of them and be quite stingy with my cutting. The pants I made with a pattern for pj pants, that I traced onto newspaper and then cut across at the crotch to give that "underwear" look. The blue shirt is just a plain long sleeve tshirt. The green shirt I actually had to size down from a 6/6x to a 3/4T, then I printed the symbol onto a iron on, ironed onto a white piece of fabric and appliqued it onto the shirt (there is actually an iron on under the applique where I tried to just iron it on but the fabric was too dark so you couldn't see it). I also sewed a snap (taken from the onesie after I hacked it up) onto each shoulder so that I could just snap his cape on. The cape is just cut from the back of a shirt, the edges (except for the bottom hem) are serged and then snaps sewn onto the top corners to snap onto the shirt. His belt is crocheted, first I crocheted around a big yellow button and then just crocheted a belt with a loop on the end to loop it around the button to hold it on (I actually made his belt in the car on the way to my mom's house on Wed., we went there to trunk or treat at her church, she lives about an hour away). I had made a mask, though it was rushed, but I knew he wouldn't wear it, so I didn't really worry about it.
In hindsight, I wish I had just made it out of fleece, it would've been much warmer, he had a pair of thermal pjs under his costume Halloween night and it was very bulky.
Here he is trunk or treating at my mom's church.

His grandpa (a recently retired Army colonel) told him to stand against the wall, so that's why he looks so serious.

Action shot

A better shot of the cape, though kind of blurry

Another cape/back shot, running down the street on Halloween night

This was his first Halloween trick or treating (he's 3), and once we got past the crying about not wanting to wear the costume (candy helped grease that wheel) he really enjoyed it. Alright, I think that's everything (TV is distracting!). Thanks!