Bei Fong Flying Boars
American Apparel T-shirts are made with 100% fine jersey cotton combed for softness and comfort. (Athletic Grey and Athletic Blue contain 50% polyester / 25% cotton / 25% rayon)
This is a reference to "Avatar: The Last Airbender". Toph Beifong started a metal bending academy to teach the newly invented skill to anyone who wanted to learn. Her family crest is a flying boar, so it made sense that any sports team from her school would take that on as the mascot.