Susan Backlinie played the young swimmer who was the first victim to die at the beginning of Jaws (1975). In this film she also is the first victim to die.
This film was sometimes mistaken as a sequel to William Girdler's Grizzly (1976), mostly because it has basically the same plot, cause director, production and distribution company, producer and features Richard Jaeckel and Christopher George, who appeared in "Grizzly". There was a sequel made for Grizzly (1976) called Grizzly II: The Concert (1983), but it never got properly completed and never released into theaters and home video. A work-print of the film has surfaced on the Internet.
Dialogue coach Garrison True plays a reporter on TV in the bar.
Besides acting onscreen and being an animal trainer, Susan Backlinie served as Lynda Day George's stunt double for this film.
The "grizzly bear" that Leslie Nielsen fights is actually a North American cinnamon bear.
Shooting took place at Long Barn, California, on Todd-AO 35 film.
Andrew Prine was approached to play the role of Frank Young, but turned said offer down. Jon Cedar, who was initially considered to play the sheriff, was cast as Frank instead.
Riffed by the guys from Mystery Science Theatre 3000 (1988) under the RiffTrax name, Michael J. Nelson, Bill Corbett, and Kevin Murphy.
Both Leslie Nielsen and Richard Jaeckel were in "Airplane!" movies. Nielsen, was in the first, while Jaeckel was in the sequel.
Even though they shared no scenes in either film, both Leslie Nielsen and Michelle Stacy (the little girl) were in both The Day of the Animals and Airplane! (1980).
The animals go berserk because of the depletion of the ozone layer, but this seems to also affect the character played by Leslie Nielsen as his personality shifts drastically. No one else however seems to be affected.