My son decided to be Underdog after seeing the movie. The Underdog costume turned out so cute.
I used a plain ol' long sleeved red shirt, and I cut out a "U" from yellow felt that I sewed onto the shirt. Then, I used some royal blue material to make the cape, and tacked it to the neckline of the shirt.
For Underdog's face, I dyed a painter's cap that I got from the craft store with a light brown dye. Then, I cut out ears from black felt and sewed them on the sides. I used big googly eyes and used tacky glue to attach them to the hat. I used a black puffy ball from the craft store for the nose, which I tacky glued on as well.
The Underdog costume was so simple to make, and if my son never wanted to wear it again, we could take the cape and "U" off the shirt and he could wear it by itself.