Kolomenskoye, south of Moscow, Russia
Date: August 29 1566
Local peasants in this village located south of Moscow encountered a tall hairy humanoid entity (so-called wood goblin) in this legendary place near the banks of the River Moskva. The frightened locals quickly fled in terror. Other reports indicated that these giant hairy entities have been seen in this area on several occasions and for centuries and reputedly are able to slip into our realm from another dimension. Rumors indicated that there was a gateway or portal into another dimension in the area where large dolmens where located at the bottom of the Golosovyi gully. Decades later on there were reports of mysterious disappearances of residents in the nearby villages of Dyakovo and Sadovniki between 1825 and 1917.
No UFO report here but I thought it worth posting as it may explain their ability to be so elusive and some UFOs are also perported to be from a parallel reality.
Date: September 17 1680
Numerous witnesses heard a loud report coming from the sky and saw three tongues of flames shooting down into the fields. This occurred three times in a row. A powerful lighting struck parts of the city causing some fires. Around the same time on the nearby fields a large black cloud-like mass descended towards the ground emitting a loud thunder like sound. From the cloud emerged a huge hair covered figure that ran swiftly across the fields. Several locals attempted to chase the creature but this one was to fast. It ran so quickly that it was able to run circles around the stunned locals. It was able to seemingly appear behind them and then in front of them in a matter of seconds. Those who were able to see it close described it as having a huge multi-colored tail, white, blue, and red. Soon after the appearance of this terrible beast a powerful storm destroyed many farms and houses in the area killing over 80 persons.