Count Yorga, Vampire: A young woman named Erica Landers, having only recently been turned into a vampire by the Bulgarian count, Yorga, massacres a kitten for its blood.
Ginger Snaps: In the 2000 Canadian film Ginger Snaps, a small boy was playing in a sandbox when he found the bloodied paw of his pet dog, Baxter. His mother found the eviscerated remains of the family pet, Baxter, and grew hysterical. Scooping up the child, she ran out into the street screaming, "It killed our dog!" Baxter's killer was actually a werewolf that later bit Ginger Fitzgerald.
Hybrid: A wolf catches a slow-moving bison, and eats it for dinner. Another wolf suffers a fatal injury. His eyes are salvaged and used in the first ever eye transplant conducted on a human subject. Naturally, the recipient develops the predatory instincts of a wolf.
Nightmare on Elm Street, A (2010): The character of Kris Fowles owned a pet dog named Rufus. While having a nightmare, she ran from her house and found Rufus' slashed remains near some bushes. As she turned screaming, she saw the dream demon Freddy Krueger brandishing blood-stained metal claws intoning, "I was just petting him". As this was just an element of Kris' nightmare, it is likely that Rufus did not die in reality. Unless dogs actually do dream, in which case he's probably f--cked.
Phase IV: Scientists Ernest D. Hubbs and James R. Lesko examined several cattle mutilations in the town of Paradise City, Arizona. They concluded that the deaths were caused by hyper-intelligent colonies of ants, whose intellect was enhanced due to cosmic phenomenon.