Myths

Cerberus
Cerberus is a well known creature in ancient mythology. Hades’ loyal guard dog, Cerberus was a massive hound with three heads that guarded the entrance to the underworld. It was said that the beast only had an appetite for living flesh and so would only allow deceased spirits to pass, while consuming any living mortal who was foolish enough to come near him. It is said that the three heads were meant to symbolize the past, present and future.

Cerberus is probably best known as the twelfth and final labor that Heracles performs.
Heracles must enter the underworld, wrestle the beast using no weapons, and then bring Cerberus to the surface world, alive, to present to the Mycenaean king Eurystheus. Heracles tackled the beast; then using his great strength, throws the animal over his shoulder and drags him to the mortal world. Upon seeing Cerberus, Eurystheus was so terrified that he hid in a large vase and begged Heracles to return the hell hound back to Hades.
The domain of Hades in Greek mythology was not only hell, but was the whole of the afterlife. The realm was Tartarus (hell), the Asphodel Meadows (nothingness), and the Elysian Fields (paradise).
Agostino Carracci (1557–1602)
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The Crocotta
The crocotta is a mythical dog-wolf of India or Ethiopia, linked to the hyena and said to be a deadly enemy of men and dogs. Pliny variously described the crocotta as a combination between dog and wolf or between hyena and lion.

"its eyes have a thousand variations of color; moreover that when its shadow falls on dogs they are struck dumb; and that it has certain magic arts by which it causes every animal at which it gazes three times to stand rooted to the spot."
"In Ethiopia there is an animal called crocottas, vulgarly kynolykos [dog-wolf], of amazing strength. It is said to imitate the human voice, to call men by name at night, and to devour those who approach it. It is as brave as a lion, as swift as a horse, and as strong as a bull. It cannot be overcome by any weapon of steel."
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The Basilisk
In European legends, a basilisk is a legendary reptile said to be king of the serpents and to have the power to cause death with a glance. According to Pliny the Elder, the basilisk of Cyrene leaves a wide trail of deadly venom in its wake, and its gaze is likewise lethal; its only weakness is the odor of the weasel.

The legend of the basilisk and its association with the weasel in Europe may be inspired by accounts of Asiatic snakes (such as the king cobra) and their natural predator, the mongoose.
Stories gradually added to the basilisk's deadly capabilities, such as describing it as a larger beast, capable of breathing fire and killing with the sound of its voice.

Some even claimed it could kill not only by touch, but also by touching something that is touching the victim, like a sword held in the hand. Some stories even claim its breath to be highly toxic and will cause horrible death.
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Ichthyocentaurs
In late Greek mythology ichthyocentaurs were a race of centaurine sea-gods with the upper body of a human, the lower front of a horse, the tail of a fish, and lobster-claw horns on their heads. The best-known members of this race were Aphros and Bythos, two half-brothers of the wise centaur Chiron. The sea-centaurs were probably derived from the divine fish of Syrian mythology.

Ichthyocentaurs upper bodies took the form of a human torso down to the hips, and the lower that of a fish, with two horse legs protruding from this intersection.

Bythos and Aphros
Some ichthyocentaurs wore crowns while others were depicted with horns often resembling crustacean claws. These two sea-gods, though little remembered, were set in the sky as the astronomical constellation Pisces.
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Hellhounds
A hellhound is a supernatural dog in folklore. A wide variety of hellish supernatural dogs occur in mythologies around the world. Some European legends state that if someone stares into a hellhound's eyes twice or more, that person will surely die.

Hellhounds often have fire-based abilities and appearance. They are often assigned to guard the entrances to the world of the dead, such as graveyards and burial grounds, or undertake other duties related to the afterlife, such as hunting lost souls. In European legends, seeing a hellhound or hearing it howl is an omen or even a cause of death. They are said to be the protectors of the supernatural.
In Greek mythology the hellhound belonged to Hades, the Greek god of death and the underworld. It's name in Greek mythology is Cerberus. It has three heads and guards the gates of hell.

The Bearer of Death is a term often used in describing the Hellhound. Hellhounds are said to be as black as coal with a smell of burning brimstone. They leave behind a burned area wherever they go.

Hades with Cerberus - Pluto Carricci painting
Hellhounds of myth is common across Great Britain and Western Europe.

In southern Mexico and Central America folklore, the Cadejo haunts travelers who walk late at night.
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The Valkyries: Chooser of the Slain
In Norse Mythology Valkyries are female warlike virgins, who are mounted on horses and armed with helmets and spears. They decide who will die in battle. They hover over the battlefield like birds of prey.

In ancient Norse mythology, before they were linked to Odin and Ragnarok, the Valkyries were sometimes represented in carvings as carrion-eating ravens. The original Valkyries, appearing on battlefields as soon as the fighting was over, would weave tapestries from the intestines of slain warriors and feed corpses to their pet wolves.
Between the 3rd and 11th centuries, the perception of the Valkyries changed and they became associated with Odin. On the battlefield the Valkyries chose the souls of the bravest slain warriors to become Einherjar, soldiers to fight for Odin at Ragnarok, the final battle between the gods and the giants. Half of those who die in battle would go to Valhalla. The other half will go to the goddess Freya’s afterlife field Folkvangr. Freya always has the first pick, of the fallen Vikings. Odin allows some of the maidens to take the form of beautiful white swans, but if a Valkyrie is seen by a human without her swanlike disguise, she will become an ordinary mortal and can never return to Valhalla.
Once in Valhalla the dead warriors became Einherjar. (Old Norse "single fighters") Inside Valhalla the Valkyries changed clothes. Wearing simple white robes, they served the Einherjar fine foods, such as wild boar, and sacred wine made from honey. They would remain the Einherjar's servants until Ragnarok.
Valkyries were Odin's bodyguards and messengers. Mortals saw their flickering armor and light streaming from their spears. In the Middle Ages Scandinavians believed the northern lights (aurora borealis) were the Valkyries flying across the night sky. Valkyries usually appeared in groups of nine.

The Ride of the Valkyries is the popular term for the beginning of Act III of Die Walküre, by Richard Wagner. The main theme of the ride was first written down by the composer on 23 July 1851. It is one of Wagner's best-known pieces.

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Gorgons
In Greek mythology, a Gorgon is a female creature. The name derives from the ancient Greek word gorgós, which means "dreadful". The term commonly refers to any of three sisters who had hair made of living, venomous snakes. They turned those who beheld them to stone. Traditionally, while two of the Gorgons were immortal, Stheno and Euryale, their sister Medusa was not, and she was slain by Perseus.

Gorgons were a popular image in Greek mythology, images of the Gorgons were put upon objects and buildings for protection.
The concept of the Gorgon is at least as old in classical Greek mythology as Perseus and Zeus. One of the earliest representations is on an electrum stater from Parium. Other early eighth-century examples were found at Tiryns. Going even further back, there is a similar image from the Knossos palace, dating to the fifteenth century BC.
See----->http://psjfactoids.blogspot.ca/2017/01/medusa.html
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