Grizzly II: The Predator

Grizzly II: The Predator (also known as Grizzly II: The Concert) was a planned sequel to the 1976 thriller film Grizzly.

Plot
Not much can be said about the plot, but based on the alternate title, what we can mostly get from it is a killer grizzly bear causing havoc at a rock concert.

Why It Was Cancelled
Executive producer Joseph Proctor disappeared with all of the fundings after main scenes were filmed and prepared to use an electromechanical bear for special effects; most sources say he was jailed during the time of filming.

Result
In spite of attempts to recut and film more scenes, the film has never been released. The closest thing we have to the actual film is a bootleg released in 2007.