I now think that Del Torro may be making a vampire movie inspired by the legends of the Chupacabra…

The chupacabras (Spanish pronunciation: [tʃupaˈkaβɾas], from chupar “to suck” and cabra “goat”, literally “goat sucker”) is a legendary cryptid rumored to inhabit parts of the Americas. It is associated more recently with sightings of an allegedly unknown animal in Puerto Rico (where these sightings were first reported), Mexico, and the United States, especially in the latter’s Latin American communities. The name comes from the animal’s reported habit of attacking and drinking the blood of livestock, especially goats.

Physical descriptions of the creature vary. Eyewitness sightings have
been claimed as early as 1995 in Puerto Rico, and have since been
reported as far north as Maine, and as far south as Chile, and even being spotted outside the Americas in countries like Russia and The Philippines.
It is supposedly a heavy creature, the size of a small bear, with a row
of spines reaching from the neck to the base of the tail.

The first reported attacks occurred in March 1995 in Puerto Rico. In this attack, eight sheep were discovered dead, each with three puncture wounds in the chest area and completely drained of blood. A few months later, in August, an eyewitness, Madelyne Tolentino, reported seeing the creature in the Puerto Rican town of Canóvanas, when as many as 150 farm animals and pets were reportedly killed. In 1975, similar killings in the small town of Moca, were attributed to El Vampiro de Moca (The Vampire of Moca). Initially it was suspected that the killings were committed by a Satanic cult;
later more killings were reported around the island, and many farms
reported loss of animal life. Each of the animals were reported to have
had their bodies bled dry through a series of small circular incisions.

The most common description of chupacabras is a reptile-like being, appearing to have leathery or scaly greenish-gray skin and sharp spines or quills running down its back. This form stands approximately 3 to 4 feet (1 to 1.2 m) high, and stands and hops in a similar fashion to a kangaroo. In at least one sighting, the creature was reported to hop 20 feet (6 m). This variety is said to have a dog or panther-like nose and face, a forked tongue, and large fangs. It is said to hiss and screech when alarmed, as well as leave behind a sulfuric stench. When it screeches, some reports assert that the chupacabras’ eyes glow an unusual red which gives the witnesses nausea.

Another description of chupacabras, although not as common, describes a strange breed of wild dog.
This form is mostly hairless and has a pronounced spinal ridge,
unusually pronounced eye sockets, fangs, and claws. It is claimed that
this breed might be an example of a dog-like reptile. Unlike
conventional predators, the chupacabras is said to drain all of the
animal’s blood (and sometimes organs) usually through three holes in the
shape of an upside-down triangle or through one or two holes.