Radar magazine takes a bite out of Jim Carrey in its third relaunch issue, on stands Feb. 13.

Labeling Carrey "unpredictable," the mag blames the collapse of some recent projects on his "bizarre behavior and on-set tantrums."

Apparently he annoyed colleagues after he "unzipped his fly and urinated" during a scene on his upcoming film, "The Number 23" - a touch that wasn't in the script.

"Dealing with Carrey proved so harrowing for 'Fun With **** and Jane's' director [Dean Parisot] that he now refers to the film as 'Fun With Jane,'" the story claims.

"He was scary," a "Lemony Snicket" exec says. "When producers ... expressed the studio's concerns to Carrey, director Brad Silberling recalls, the star bristled. He said, 'You should stop right now, because what you're about to say may mess up my creativity for the rest of this movie.'"

Three big Carrey films since last year have been delayed or canned, including "Used Guys" with Ben Stiller and a Cameron Diaz project.

Carey declined to be interviewed for the article, and his reps did not comment yesterday.