Boo 3: With Wonder Bread 5, 8 p.m., $13-$30. Red Devil Lounge, 1695 Polk (at Clay), 921-1695.
Diamondhead Halloween Weekend: Featuring Super Diamond and Notorious singing selections of Neil Diamond, 9 p.m., $20. Slim's, 333 11th St. (at Folsom), 522-0333.
The Fly: The original 1958 cautionary tale of science, man, and fly gone awry, 7:30 p.m., $4-$8. Pacific Film Archive, 2575 Bancroft (at Bowditch), Berkeley, 510-642-5249.
GayGlo Halloween Show: Spectacular and unique glowing musical revue at the Castro's main stage, 8:45 p.m., free. Castro Street, (at Market).
Hallofest!: Huge indoor/outdoor party featuring performance artists, dancers, costume contests, and DJs spinning hip hop, trance, deep house, rock, and more, 9 p.m.-5 a.m., $30-$75. Kelly's Mission Rock, 817 China Basin (at Mariposa), 626-5355.
Halloween Ball: With Stug, Zoo Station, and costume contest, 9 p.m., $9. Last Day Saloon, 406 Clement (at Sixth Ave.), 387-6343.
Halloween Bash: Rotating DJs, costumes encouraged, 9 p.m., free. Bubble Lounge, 714 Montgomery (at Jackson), 434-4204.
Halloween in the Castro: A Halloween mecca of revelry, outrageousness, and hard-core trick-or-treaters. Castro Street, (at Market).
Halloween Masquerade Ball: With DJs Donovan and Frenchy Le Freak, 9 p.m. The W Hotel, 181 Third St. (at Mission), 777-5300.
Halloween Party: With DJs Mei Lwun and Johnny Knight, 9 p.m.-3:30 a.m., $25. Suite one8one, 181 Eddy (at Mason), 345-9900.
Halloween Show: Featuring Metric, On the Speakers, and The Sleaves, 10 p.m., $7. Bottom of the Hill, 1233 17th St. (at Missouri), 621-4455.
Hallowqueen: First annual Halloween drag king and queen contest, 6 p.m., $25. Castro Theatre, 429 Castro (at Market), 621-6120.
Lingba Witch Trials Halloween Party: Lingba transforms into a haunted jungle, 9 p.m.-2 a.m., free. Lingba Lounge, 1498 18th St. (at Connecticut), 355-0001.
Mad Scientists Halloween Blast: With Van Boven, Cheap Ass Robots, Tri-Cornered Tent Show, Helium Karaoke, Pengo, and The Autumn Project, 9 p.m., $5-$15. 21 Grand, 449B 23rd St. (between Broadway and Telegraph), Oakland, 510-444-7263.
The Mansions: Nifty Tom Fifty, One Light Out, Betaville come dressed as your favorite rock star, 9 p.m., $5. Tongue & Groove, 2513 Van Ness (at Union), 928-0404.
Meat: Devil's Night: With DJs Devon, Ritch, Mitter Gluck, and Netik, 9 p.m.-2 a.m., $5-$7. DNA Lounge, 375 11th St. (at Folsom), 626-1409.
The Meatball: Costume jamboree with hostess Heklina, Kennedy, Michael Soldier, Pepperspray, Dirty Sanchez, Felix Da Housecat, contests, and more, 10 p.m.-6 a.m., $10. Space 550, 550 Barneveld (between Industrial & Oakdale), 550-8286.
Night of the Living: Costume party featuring DJs Spesh, Ellen Ferrato, Dragn'fly, Laird, and more. Bring item for Day of the Dead alter, too, 9 p.m.-5 a.m., $15. Gingerbread Warehouse, 1275 Connecticut (at Cesar Chavez), 640-1798.
Son of Drakula: See David Drake's new play, plus a costume party before heading to the Castro, 7 p.m., $28. New Conservatory Theatre Center, 25 Van Ness (at Market), 861-8972.
Stage Frights: Plays From Hell: See Friday.
This House Is Haunted -- Legends of House 5.0: Featuring DJs Joe Smooth, Wayne Williams, Jesse Saunders, Sen-Sei, David Coleman, and Ernan, 9 p.m.-4 a.m., $10. Club Six, 60 Sixth St. (at Jessie), 863-1221.
Thundercrack: 11 p.m. Roxie Cinema, 3117 16th St. (at Valencia), 863-1087.
Saturday, Nov. 1
Day of the Dead Skulls: Celebrate Día de los Muertos by designing a skull inspired by the Randall's animal skull collection, 1-4 p.m., $3. Randall Museum, 199 Museum Way (at Roosevelt), 554-9600.
Día de los Muertos: Celebrate the day with decoration of traditional ofrenda and music by Ernesto Hernández Olmos, 10-4 a.m., $5.50-$8.50. California Academy of Sciences, 55 Concourse (at JFK), Golden Gate Park, 750-7145.
Fright Night: Presented by Midnight Mass Season of Horror and your hostess Peaches Christ. Spooky and silly pre-show included. Be sure to buy tickets early, as they sell out soon, $8. Bridge Theater, 3010 Geary (at Blake), 751-3213.
Halloween Haunts at Hidden Villa: See Saturday.
Them! and The Thing: 2:30, 5:45 and 9:10 p.m., $5-$7. Auctions By The Bay Theater, 2700 Saratoga (at West Red Line), Alameda, 510-740-0220.
Sunday, Nov. 2
Death and Rebirth: Annual celebration of Día de los Muertos, 7-10 p.m., free. Precita Eyes Mural Arts & Visitors Center, 2981 24th St. (at Harrison), 285-2287.
Día de los Muertos Exhibition: Artists' exhibits of the dead, 6:30-11 p.m. Mission Cultural Center, 2868 Mission (at 25th St.), 821-1155.
King Kong: 7 and 9:15 p.m., $5-$7. Auctions by the Bay Theater, 2700 Saratoga (at West Red Line), Alameda, 510-740-0220.