T-shirt design suggestions for an event?

I have organized a flag football game on the first Saturday of the year for the past nine years. It’s grown to almost 40 guys and includes a soundtrack, referees, trophies and chili afterwards. It’s call the Snowbowl and because this is the 10th year, I’ve been thinking about T-shirts. I would love the T-shirts to be cool and fun, but not necessarily comical. I’m also trying to think of a tagline that is witty or funny. Any suggestions on a design or a tagline for this event? My roommate is a cartoonist and is fairly capable of drawing many a thing. Any suggestions are welcome! Thanks!!