Boo. And behold: Halloween happenings for Saturday night, 10/27.

-- Karla LaVey's Satanic Halloween Party & Unholy Variety Show: Satan reigns supreme tonight "thrashing black-metal bands, theremin warblers, psychobilly greasers, cruel electronic-noise wizards, 'tranceformer' dancers, cinematic oddities, and, of course, vast oceans of demon liquor" (all liquor is demonic liquor, blasphemer!) Starts at 8 p.m. at the The Knockout; sliding-scale admission.

-- Surya Dub Halloween Mashdown: What's scarier than hanging out at Sixth Street and Market during the midnight hour? Nothing, that's what. Dubstep, bass, breaks, ragga, and titular mashups sounds abound at this Halloween party. Goes from 9 p.m. to 4 a.m. at Club Six; $10.

-- 1984: Hell-O-Ween Addition: As if the '80s weren't scary enough, this Reagen-era club night will put on quite the Hallowen show. DJs Damon & Jules call forth from the grave a tribute to hair metal. Eeeps! Starts at 9 p.m. at Cat Club; $10.

-- Bigger Is Better Halloween Ball: Bayview arena club gets even more smutty. Expect sluts, spooks, scares, screams (of joy!), and decadent sounds to get your swooning on the dance floor this evening. Starts at 10 p.m. at Space 550.