“Rink Rat Roller Derby” is the theme on Saturday when Southside Revolution Junior Roller Derby hosts Tacoma’s Tomorrowland Junior Roller Derby at Southgate Roller Rink> in White Center. Before the two rounds featuring two teams each, you can watch a “derby demo” featuring Southside’s newest cadets and “some friends from SSR Resistance.” It’s a full evening of high-energy fun, with doors opening at 4:15 pm at 9676 17th SW, and the night wrapping up arund 8 pm. Admission is $10 youth, $15 adults, and SSR’s announcement adds, “Bring extra cash to support our league by purchasing treats at the bake sale and SSR merchandise!” You can also buy tickets online in advance.