‘Ma’: Octavia Spencer gone wild — and wicked

“Ma” is one loony little horror film, and Octavia Spencer has a grand old time being the craziest thing in it. She goes all in as Sue Ann, a misfit loner with a fondness for hypodermic needles and Debbie Deb tunes.

It’s a bizarre role; after all, who ever expected to see the gifted Oscar winner gleefully sewing together the lips of a blabby blond teenager? But Spencer layers the part with an underlying pathos that can be unexpectedly touching. It’s like she’s Bette Davis and this is her “What Ever Happened to Baby Jane?”

The film takes its time getting to the creepy stuff, which gives director Tate Taylor plenty of room to develop the characters. (He directed “The Help,” which brought Spencer her Academy Award.) Maggie (Diana Silvers, quite good) is a 15-year-old who moves from San Diego to the downtrodden Ohio town where her mom, Erica (Juliette Lewis), grew up. It’s the kind of place where Erica’s old classmates still reside, including hunky widower Ben (Luke Evans) and sloppy drunk Mercedes (Missi Pyle).

Maggie quickly makes friends. She and her new pals meet Sue Ann one day when they are outside a liquor store, trying to convince strangers to buy them booze. Sue Ann acquiesces after some minor protesting. Also, rather sweetly (and, needless to say, inappropriately), she displays a motherly concern for their safety.

Eventually Sue Ann offers up her basement as a party spot for the teens. This way, she says, she can keep an eye on them and make sure no one drives home drunk. She also lays down some ground rules: Don’t take the Lord’s name in vain, don’t spit on the floor and never venture upstairs. This being a horror film, that last part is crucial.

Soon, Sue Ann — now affectionately known as “Ma” to the kids — is partying with an increasing number of high schoolers while the stereo pumps out songs from her youth. Another unexpected sight: Sue Ann dancing to “Kung Fu Fighting” while she’s kicking down a tower of beer cans. Hey, no one can say the film is predictable.

In fact, the script by Scotty Landes moves in all sorts of directions and is often quite surprising. It creates an odd sensation in that it feels familiar — certain scenes bring to mind “Prom Night,” “Carrie” and “Misery” — but it somehow feels original at the same time. It’s not always logical and is often downright batty as it bounces from domestic drama to teen romance to cringey torture porn, but it’s never less than compelling.

Taylor slips in some unexpected tonal changes that shouldn’t work, but do. A gruesome murder occurs to the jaunty counterpoint of Earth, Wind & Fire’s “September,” for example. There is also a kicky sense of humor. Sue Ann works as a veterinary assistant for the heartless Dr. Brooks. Allison Janney has a ball as Brooks: ”Go take some horse tranquilizer!” she barks after Sue Ann meekly complains of having a headache.

Still, this is Spencer’s film, and she dominates. As lonely Sue Ann descends deeper into madness, the actress displays a remarkable ability to flip from menacing to motherly without ever slipping into caricature. The character’s awkward, overbearing attempts to bond with the teenagers ring with truthfulness, as does her misplaced hope during a reunion with a former high-school classmate.