VENICE (Reuters) - Music video Thriller was not the product of a brilliant idea but was made because pop star Michael Jackson wanted to be a monster, director John Landis said at the Venice film festival on Monday.

He was in the city to present the 3D version of the video which was made 35 years after the original. It was screened as a special event in the out-of-competition section.

"(Thriller) was nobody's good idea, it was no brilliant business plan," Landis said.

"It was a vanity video because Michael wanted to be a monster. And everything that came, evolved from that, was spectacularly successful and I was totally surprised."

Landis said Jackson first approached him about making the video because he liked his work on the movie An American Werewolf In London.

The two, along with make-up artist Rick Baker, met to look at photographs from old monster movies.

"He wanted zombies but the big thing for Mike was turning into a monster."

Asked about his first meeting with Jackson, who died in 2009 at 50, Landis said he was "joyful" and "child-like" and quickly became a close family friend.

"Michael was very determined that everything had to be the best, the greatest," he said.

"He had a spectacular work ethic, but he was an old pro, the guy has been performing since he was eight years old."

Landis jumped at the idea of converting Thriller into 3D because "I really wanted you to experience it the way Michael wanted you to experience it".

"We went through the whole movie frame by frame, and it was not intended to be in 3D, so we are not throwing anything at you or anything like that, but it does enhance certain parts of it tremendously... the dance is much improved," he said.

"My only disappointment is that Michael is not here to see it and hear it because I think he would love that," he added.