Weird but true: "21 Jump Street" heartthrob Johnny Depp will team with quirky film maker John Waters ("Pink Flamingos," "Hairspray") - for the musical love story "Cry Baby."

A spoof of '50s-era JD (that's juvenile delinquent) flicks, it is for Imagine Entertainment-Universal. Waters will write and direct with Rachel Talalay producing.Depp will play a gang member who gets his "Cry Baby" nickname when he is spotted shedding a single tear. The picture boasts more than 30 tunes, but Depp may or may not sing. His spokesman reminded, "Johnny broke in as a singer-musician," playing clubs in Hollywood.

Filming is set for Waters' Baltimore stomping ground in mid-April. That is hiatus time for Depp from his work as a sexy undercover cop on "Jump Street," where he has emerged as the hot star at age 25.

But some film offers will have to wait.

"When this season ends," said a Fox TV spokesman, "Johnny Depp's contract continues for three more years."

And Fox's teen beat continues: "The Outsiders" - Francis Coppola's 1983 teen epic, the original Brat Pack movie - may become a TV series, with Coppola as an exec producer. A Fox Broadcasting representative confirmed that an "Outsiders" pilot is in development as a possible addition to Fox's new Monday night lineup, to bow in September.

Casting has begun under co-exec producer Fred Roos, who produced the original film - based on the popular novel by S.E. Hinton, who will also be involved.

Like the film, the series will be set in the 1966 Midwest, depicting rivalries and relationships of the poor "greasers" and the wealthy "socs" (pronounced soashes).

The 1983 film starred C. Thomas Howell (Ponyboy), Patrick Swayze (Darrel), Rob Lowe (Sodapop), Matt Dillon (Dallas), Ralph Macchio (Johnny), Emilio Estevez (Two-Bit), Tom Cruise (Steve), Diane Lane (Cherry) and Leif Garrett (Bob). - PAT H. BROESKE

- The Devil Made Him Do It:

HOLLYWOOD - "Exorcist III," in development for years, is finally getting ready to go before the cameras in May. It is based on William Peter Blatty's 1983 novel, "Legion" - which had no satanic possession in it. So Blatty, who wrote the screenplay for "III" and will direct, put an exorcism in his script to capitalize on the title.

"The question was not to have one or not in the movie," he said, "but what significance to give it."

Strictly speaking, "Legion" was not a sequel to Blatty's best seller "The Exorcist" (1971), which became the smash film hit of the same title two years later. Columbolike detective William Kinderman was featured in both books, but "Legion" had nothing to do with exorcism. Instead, Kinderman was embroiled in an investigation of a series of grisly, ritualistic murders, which will be an element in "III."

Some history: Blatty maintained all sequel rights to "I," allowing Warner Bros. a one-time option for "Exorcist II: The Heretic" (1977), a monumental critical and box office bomb. "III" was in development at Weintraub Entertainment, but is now at Morgan Creek Productions.

Jason Miller, Oscar-nominated for his portrayal of Father Karras in "I," will return in "III." The demon killed Karras in the original, but Blatty won't reveal how the priest returns.

"That's part of the mystery," Blatty said devilishly. -LEONARD KLADY

- Cinefile:

HOLLYWOOD - Martin Short plays the title role in Universal's "The Curious Case of Benjamin Button" for producer Ray Stark. Tom Pope adapted the F. Scott Fitzgerald story about a child born as an old man who grows progressively younger with each birthday. Frank Oz directs with production set for April.

Bob Hoskins and Denzel Washington team up for New Line's "Heart Condition," a comedy set for a May start in Los Angeles. The Steve Tisch production casts Hoskins as an intolerant cop whose chief adversary is lawyer Washington. Dual freak accidents result in Hoskins receiving his opponent's heart, inheriting his ghost-plus the task of solving his death. James Parriott writes and directs.

Ally Sheedy will next be seen as a psychic abetting the police in a murder investigation in Vestron's "Fear." Michael O'Keefe is her police contact in the Richard Kobritz production which Rockne O'Bannon wrote and will direct in April. . . . Meanwhile, Brooksfilm has signed writer Judith Rascoe to adapt Marsha Norman's novel "The Fortune Teller," in which Anne Bancroft will star as a psychic involved with the pursuit of a serial killer. Roger Spottiswoode is attached as director and Mel Brooks and Merv Griffin are exec producers. The Tri-Star release won't film until the fall.

Richard Gere takes on an adversarial role when Andy Garcia checks into police corruption in Paramount's "Internal Affairs," filming next month. Mike Figgis directs the Henry Bean original screenplay. . . . Anthony Edwards and Forest Whitaker are police partners in Fox's "Downtown," a Gale Anne Hurd production scheduled for April. The Philly-set thriller finds the inexperienced Edwards put into the line of fire, with Whitaker reluctantly teaching him the rules of the mean streets. Richard Benjamin directs the Nat Mauldin screenplay. . . . Writer Mauldin also signed for the plum assignment of creating Disney's "Roger Rabbit II."

Laurel Entertainment's long-cherished adaptation of Stephen King's "The Stand" also has a new writer. Director George Romero inked Rospo Pallenberg ("Excalibur") to do the adaptation. . . . Actor Jeffrey Combs cooks up more strange experiments in Wild Street Production's "Re-Animator II," a May start. Dennis Paoli wrote the sequel that Brian Yuzna directs and co-produces with Keith Walley. . . . Brad Dourif discovers his smoldering finger is just the beginning of "Spontaneous Combustion," a Project Sampson film co-written and directed by Tobe Hooper.

Jason Bateman plays a terminally ill young man whose two best friends take him on a cross-country romp in MCEG's "Sketches," going on the road in March. Jonathan Krane produces and Neal Israel directs his original screenplay. . . . Veteran actor Hal Holbrook makes his big-screen directorial debut with "Stagger Wing," an indie effort scheduled to film in Arkansas May 1. Ron Loveless and Harry Minetree produce the story of a small town transformed by the arrival of a stranger.

- THE MOVIE CHART:

Films now going into production:

BACK TO THE FUTURES 2 AND 3 (Amblin). Shooting in Los Angeles. The core creative people from first one (exec-producer Steven Spielberg, director Robert Zemeckis, players Michael J. Fox, Lea Thompson and Christopher Lloyd) return to film two sequels thus taking advantage of Fox's free time. Details are limited; and it's rumored that Spielberg has forbidden even himself from peeking at the script. Producers Bob Gale and Neil Canton. Screenwriters Zemeckis and Gale. Also stars Thomas F. Wilson. Distributor Universal. Winter '89 and Summer '90 releases.

BROWN BREAD SANDWICHES (Brown Bread Sandwiches). Shooting in Toronto. Giancarlo Giannini, Lina Sastri and Kim Cattrall star.