Mom and Dad ★★★½

'Mom and Dad' starts with a premise that echoes 'Parents' (1989) and the recent 'Don’t Grow Up': One day, parents are suddenly consumed with a monomaniacal urge to murder their children. The specificity of this perverse conceit — adults only want to butcher their own kids, not *all* kids — allows writer-director Brian Taylor to maintain a giddily satirical atmosphere throughout the blood-spattered proceedings, even when the plot shades into jaw-dropping transgressive horror. (In one appalling scene, a woman gives birth and then attempts to suffocate her minutes-old infant.) Nicolas Cage’s unchained inclinations as an actor fit comfortably with the film’s deranged events, and also with Taylor’s occasionally over-cranked direction. At one point, Cage’s seething, resentful dad destroys a pool table with a sledgehammer while maniacally singing “The Hokey Pokey.” ’Nuff said. 'Mom and Dad'’s secret weapon, however, is Selma Blair, whose comic talent for disbelieving eye-rolls and gooey faux-sincerity is on full display — as is her proficiency with a meat tenderizer.