Photo by Rachel Carrier.

MUSIC: Dig out those clothes you don’t mind getting stained with fake blood — GWAR is coming to the 9:30 Club (815 V Street NW) with The Casualties, Infernaeon and Mobile Deathcamp. 6 p.m.

>> Cobra Collective has canceled their performance at the Black Cat (1811 14th Street NW) due to “a case of pneumonia,” but Triggers and Third Programme are still lined up to perform. $8, 9 p.m.

>> U Street Music Hall (1115A U Street NW) presents Future Times/The Whale Holiday Party tonight with Runaway, Beautiful Swimmers and Mondo. 10 p.m. Free.

FOOD & DRINK: Bier Baron (1523 22nd Street NW) opens tonight stocked with 350 beers leftover from the Brickskeller. They’re calling it their “Brickskeller blowout” menu. 6 p.m.

>> Head to Mad Fox (444 West Broad Street, Suite I, Falls Church) for “Meet the Brewers Night” and pick the brains of Mad Fox brewers Bill Madden and Charlie Buettner. 5-7 p.m.

MOVIE: Embrace your inner 8-year-old and go see Tron: Legacy 3D, recently reviewed by DCist’s Ian Buckwalter here and here, at Uptown Theater (3426 Connecticut Avenue NW). 7:15 p.m. $14.75.

STARS: Tonight is the third Night at the Planetarium fundraising event at the David M. Brown Planetarium (1426 N. Quincy St. Arlington). There will be three programs including “Legends of the Night Sky,” “Black Holes, The Other Side of Infinity” and “Oasis in Space.” 4:30-9 p.m. $10.