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

Kappa (November 1978, Yokosuka, Japan)

Two construction workers by the names of Makoto Ito and Toshio Hashimoto were fishing off a stone seawall near the US Navy Base in the Japanese port city of Yokosuka when they saw something they would never forget. Ito recalls that ‘It just popped up from beneath the surface and stood there. It was not a fish, an animal or a man. It was about 3 meters in height and was covered in thick, scaly skin like a reptile. It had a face and two large yellow eyes that seemed to be focused on us.’ The witnesses described this entity as a Kappa, which is a mythological creature from Japan that resembles a hybrid of a monkey and a turtle. They effectively act as water goblins that are prone to stealing livestock and attacking swimmers. I’m not sure if the description of this entity as being 3 meters tall is correct, or if the witness meant to say it was 3 feet tall. If the former is correct, then this sounds more like a lizardman sighting.
Source & Image Credit: The Field Guide to Bigfoot and Other Mystery Primates by Loren Coleman, Patrick Huyghe & Harry Trumbore

Merbeing (November 1737, Coast of Exeter, Devon, England)

Fishermen on the shore caught a four-foot-tall humanoid, with duck-like feet and a tail protruding from its back. It tried to escape but was killed when the fishermen beat it with sticks (like humans apparently do whenever they encounter something weird). Another fish-man was caught a few months later in the same area, though this one was described with more seal-like qualities. There are actually a surprisingly large amount of merbeing sightings that were reported in 1737 - and so maybe they were following some kind of a migratory pattern?
Source: 'Humanoid Encounters' by Albert Rosales
Image Credit: http://www.britishmuseum.org/research/collection_online/collection_object_details.aspx?objectId=3370709&partId=1&subject=16589&page=2

Merbeing (January 10th, 2008, Suurbraak, Western Cape, South Africa)

While enjoying a 'braai' (barbeque) on the banks of the local Buffelsjags River, a group of friends reported spotting a mermaid-like creature previously believed to be legendary. This entity is known as the Kaaiman in local folklore. A local resident by the name of Daniel Cupido said that he was relaxing next to the river with a group of friends when he heard something that sounded like someone 'bashing on a wall'. When he walked towards the sound, he saw a figure that he described as 'like that of a white woman with long black hair' at a nearby low water bridge. She was allegedly 'thrashing about in the water' and so Cupido thought to try and save her, walking towards her but stopping in his tracks after noticing a reddish shine in her eyes. This sight 'sent shivers down his spine', yet he was pulled forwards towards her as if hypnotised. He called out for his child, who was called Deidrian and was 13 at the time, and his nephew, Werner Plaatjies, 11. When they came to help him, they broke him out of the trance, and he then yelled for his friends to take a look at the supposed mermaid as well.
Later, Martin Olckers said that he saw a female figure swimming on one side of the low water bridge, and then on the other, before standing on the bridge and diving back into the water. He said that the figure made a sound like a woman crying, and his mother, Dina, said that the sound was so sorrowful that her 'heart could take it no more'. Dina's husband Martinus said that their parents had warned them about the Kaaiman, but they had never believed that it existed. Some people allege that the Kaaiman is responsible for recent drownings.

Source: “Sighting of legendary river mermaid in Western Cape,” Herald, West Cape News by Aldo Pekeur

Image Credit: https://targete.deviantart.com