There are inessential Fringe shows, and then there’s actors in suits doing middling celebrity impressions for an hour. That isn’t to say “Repertoire Dogs” is bad, exactly. It’s fun watching host Josh Carson guide an array of local all-stars through OK impressions of luminaries ranging from George W. Bush to Carol Channing to Kermit the Frog, but it’s nothing more or less than what it sounds like. If you have an open hour and think Ian McKellen and John Hurt performing a scene from “Showgirls” sounds amusing, you won’t regret catching it. But you probably won’t regret missing it either. (8:30 p.m. Thu., 4 p.m. Sat., Mixed Blood Theatre, 1501 S. 4th St., Mpls.)