This film became the most financially successful independent film of 1976, earning $39 million worldwide at the box office and breaking several other records. Halloween (1978) broke the record two years later.
Claws (1977), an unrelated independent horror film about a killer grizzly bear in Alaska, was re-released in 1978 in Canada and Mexico as "Grizzly 2" to capitalize on the success of both this film and Jaws (1975).
A Kodiak bear who was nicknamed "Teddy" played the titular role in the film. Teddy, who was 11 feet tall when standing on his hind legs, was the largest brown bear in captivity at that time. He was untamed, but was trained by an expert bear trainer with the cast and crew being protected from Teddy by a thin green electrical wire that ran through the forest locations. In addition, a mechanical bear was used for the scenes when the grizzly bear attacked people in it.
After the film had been distributed worldwide and grossed $39 million, executive producer/distributor Edward L. Montoro decided to keep the profits without paying co-producers and co-writers David Sheldon and Harvey Flaxman and director William Girdler. All three of them sued, and the Los Angeles County Superior Court eventually ordered Montoro to pay Sheldon, Flaxman, and Girdler.
The film was shot on the week before Thanksgiving Day and the five weeks after that, and "Teddy" by now was getting ready to hibernate for the winter. At times, he was grumpy because of this. During one long dolly shot for it, his trainer dangled a big fish on a pole in front of him, then switched it out with a smaller fish at the end of the run. Bears are normally not all that intelligent but, by the film's seventh take of this trick, "Teddy" had finally figured out what was going on literally right under his nose and he suddenly wheeled around toward the camera, ran about 30 feet, stood up on his hind legs and snatched the big fish off of the pole, all of which took about three seconds to do.
Harvey Flaxman: One of the film's two co-producers/co-writers (the second one was David Sheldon) plays a reporter by Charley Kittridge's (Joe Dorsey) office.