Copiapó Pterosaur (March 17th 1868, Copiapó, Chile)

When the day’s work in the mine was over and all the workers were gathered together waiting for their dinner, we saw arrive through the air on the side of the mine known as “La Ternera” an enormous bird that at first we took for the clouds that a that moment were covering a part of the atmosphere, supposing that it had been separated from other clouds by a chance gust of wind as the object in question approached, causing us great surprise, we could see it was an unknown flying object. It was moving from the northeast to the southeast and its flight was fast and in a very straight line. It passed over just above our heads and we could see the strange structure of its body. Its great wings were covered in brownish feathers, the head of the monster looked like that of a lobster and its eyes open wide and bright like embers, and it seemed to be covered in something resembling thick hair, like a sow. Its body was long like a snake’s and only bright scales could be seen on it, which sounded like metallic pieces when the strange animal moved them. Surprise soon became panic amongst the workers before such a strange phenomenon. Some claim they detected a terrible smell in those moments, a smell similar to arsenic when it is burnt. Others say their senses were not so injured in such an odd manner. The superstitious believe it was the devil himself who they saw pass over, while others remember having witnessed in that city, years ago, the passing of a similar monstrous bird.
Source: 'Return to Magonia' by Chris Aubeck
Image Credit: https://www.kryptozoologia.pl/zywe-pterodaktyle,556,24,artykul.html

Merbeing (1204, Orford, East Anglia, England)

One day around 1204, some Orford fishermen caught something unusually heavy in their nets. As they pulled and pulled on the nets in an attempt to get them back on board their boats, and saw what they thought was a large creature tangled up with the rest of their catch. They were extremely surprised when they finally managed to get their catch aboard because there, in the bottom of their boat was a man staring angrily at them. He was described as being naked but with a hairy body; having a long straggly beard and the top of his head being completely bald. Attempts to speak to him failed so the fishermen restrained him and took him back to the town. The ‘merman’ was taken to Orford castle where the castle custodian, Bartholomew de Gladville, kept him prisoner. He and the jailers tried time and time again to question this ‘merman’ but the creature only uttered grunts and strange noises. They noted that when he was fed raw fish he would squeeze the water out of them into his hands and then drink it. Bartholomew de Gladville became frustrated at the creature’s silence and he had the merman tortured by hanging him upside down by his ankles. Despite this ill treatment the merman still did not (or could not?) talk and eventually his jailers gave up. Bartholomew de Gladville then took him to the nearby church but it was obvious that the creature had never seen a church service before either. One day sometime after he was first captured, the merman was taken down to the harbor. Nets had been strung across the entrance and he was set free so that he could enjoy a swim but without escaping. He made straight for the nets and easily escaped under them and headed out to sea, leaping out of the water with joy. Although he spent a little time that day in sight of the harbor, he was never seen again.
Source: 'Humanoid Encounters' by Albert Rosales & http://www.visit-orford.co.uk/articles/the-merman-of-orford

Green Dwarf (Winter 1959, Derry, New Hampshire)

The witness was gathering Christmas trees when he encountered this ostensibly alien entity. It did not look very human, and had a high domed forehead with green and wrinkled skin. In place of an external nose, it simply had holes and it had green 'glossy' dorsal spines as well as greyish-green body hair. The feet and hands of the creature were described as being 'like stumps', and so it would be reasonable to suspect that they lacked digits. The creature sounds extremely similar to the legendary Chupacabra from this description - not to mention the fact that this thing could literally be described as a 'little green man'.
Source: Modern Mysteries of the World: Strange Events of the Twentieth Century by Janet and Colin Bord

Pooka (1990, Ashby-De-La-Zouch, Leicestershire)

A resident of the aforementioned village awoke in the middle of the night and witnessed what she believed to be a being known as a Pooka in Irish folklore, sleeping over the pelmet of a window on her landing. The creaeture looked similar to a small piglet, but had a long, pointy nose and no visible tail. Pookas are shapeshifting tricksters and mischief-makers in Irish faery lore, but as far as I know they have never been described as piglet-like entities.
Source: A Menagerie of Mysterious Beasts by Ken Gerhard

Ufonaut (December 19, 1954, Valencia, Venezuela)

18-year old jockey José Parra, out on a training run, came upon 6 very hairy little men loading rocks into a disc shaped craft which was hovering less than 9 ft from the ground. Parra started to run away, but one of the little beings pointed a device at him that emitted a beam of violet light, and he found himself paralyzed. The entities jumped aboard their craft & it took off. At the site were found footprints “neither animal nor human.”
Source: http://ufologie.patrickgross.org/ce3/1954-12-19-venezuela-valencia.htm

Ufonaut (438 AD, Istanbul, Turkey)

An earthquake has destroyed Constantinople; famine and pestilence are spreading. The cataclysm has leveled the walls and the fifty seven towers. Now comes a new tremor, even stronger than all the previous ones. Nicephorus, the historian, reports that in their fright the inhabitants of Byzantium, abandoning their city, gathered in the countryside: “They kept praying to beg that the city be spared total destruction; they were in no lesser danger themselves, because of the movements of the Earth that nearly engulfed them, when a miracle quite unexpected and going beyond all credence filled them with admiration. In the midst of the entire crowd, a child was suddenly taken up by a strong force, so high into the air that they lost sight of him. After this, he came down as he had gone up, and told Patriarch Proclus, the Emperor himself, and the assembled multitude that he had just attended a great concert of the Angels hailing the Lord in their sacred canticles. Acacius, the bishop of Constantinople, states, “The population of the whole city saw it with their eyes.” And Baronius, commenting upon this report, adds the following words; “Such a great event deserved to be transmitted to the most remote posterity and to be forever recorded in human memory through its mention every year in the ecclesiastical annals.” For this reason the Greeks, after inscribing it with the greatest respect into their ancient Menologe, read it publicly every year in their churches.
Source: 'Wonders in the Sky' by Jacques Vallee & Chris Aubeck

Centaur (41–54 AD, Rome, Italy)

Pliny the Elder claims to have seen a dead Centaur preserved in honey. It was being transported to Rome from Arabia via Egypt during the reign of Emperor Claudius. Phlegon of Tralles saw it about sixty years later and wrote that it had a fierce face and hairy arms and fingers. Its human torso merged smoothly with its horse’s body, and its hooves were firm. The entire body had turned dark brown. Obviously, there is a possibility that this entity was really a 'gaff' - a taxidermied fake made from the body of a horse and the torso of a human or monkey.
Source: ‘Mysterious Creatures’ by George Eberhart