Written and directed by Claudio Fragasso (who was credited a at the time as Clyde Anderson), Monster Dog (aka Leviatán, The Bite and Los Perros de la Muerte) opens with Vince Raven (Alice Cooper with his voice dubbed by an uncredited Ted Rusoff – in fact The only time Alice Cooper’s real voice is heard is during his two musical sequences) performing in his new music video “Identity Crisis.” Later, Vince, Vince’s girlfriend Sandra (Victoria Vera), and Vince’s film crew drive to Vince’s old childhood home to shoot another music video.
While waiting for them to arrive, the caretaker of the house, prepares a welcome home party for Vince but begins hearing strange noises. After searching around the house, he walks outside to find a pack of wild canines or Monster Dogs, growling outside his door that attack and kill him.
The next morning the crew continue their drive to the house when they come across Sheriff Morrison (Ricardo Palacios) and Deputy Dan (Luis Maluenda), who are standing at a barricade. The police warn the crew that there has been another “attack”. After the crew leave, the sheriff and his deputy are both killed by the Monster Dog in the woods.
As the drive continues, Vince hits a German Shepherd with the van. The crew cannot stand to watch it suffer in pain, so Vince puts it to rest by killing it with a large rock. While the crew mourns the dog’s death, an old man in blood-stained clothing attacks them. He warns them that they “will all die”, except for Vince. The old man then runs into the woods. Vince and Sandra chase after him. Later when they get to the house the find the carnage and Vince finds a book about werewolves…