Slutty getups, creepy masks and the obligatory topical togs (Snooki Bumpits, Gaga meat dresses … ick!) will be on display in an array of club environments this weekend, but we won't list them all here. Instead, we take on the terrifying task of narrowing it down. Here, a trio of alt/mixed monster mashes — one for each night — guaranteed to have spine-tingling sounds and wicked atmospheres. SCARY MARY: Eric Adams, Cody Bayne, Mario Diaz, Victor Rodriguez and Mike Uljanic (Otter Magic) offer $1,000 in prizes, some bewitching performers (Kelly Mantle, Miss Barbie Q, Nina McNeely & Co.) and demented DJs including Rodriguez (Shits & Giggles), Chris Bowen (Bears in Space), Matt Cornwall (Drai's at the W), DJ Pandamonium (Par Avion) and DJ Susan in Accounting (Otter Magic). Airbrush body-painting, photo booths, fortune-tellers, palm readers and aerialists. Cash awards will go to “Most Arousing, Most Cleverest, & Most Disturbing” outfits. Club 740, 753 S. Spring St.; Fri., Oct. 29; brownpapertickets.com/event/133224. KCRW MASQUERADE: Last year's ball was hands-down one of the best Hallows Eves in town. With KCRW's arsenal of spinners plus Cut Chemist and bands including Duke Spirit and Gram Rabbit playing this year, and Lucent Dossier in the house, the mystery and mayhem should be heightened as ever. Costumes at this one won't disappoint. Park Plaza, 607 S. Park View St.; Sat., Oct. 30; kcrw.com/events/masquerade-2010. THE ASYLUM BALL: Waiters in assless pants, fabulous masks and frocks and sexy hell-raising are the norm at Mr. Black, so you know it's burning up for Halloween. Black joins Cherry Pop to take over the Factory and Ultra Suede in WeHo, with hosts Ernie Omega, Miles Devin and Lenora Claire. DJs include Brynn Taylor, Josh Peace, Derek Montiero and Nelstar. Masters of ceremony Tom Whitman and Luke Nero commence the dance floor bloodbath. 661 Robertson Blvd., W. Hlywd.; Sun., Oct. 31; mrblackla.blogspot.com.