AboutThe Blackbird of Chernobyl is a most likely fictional internet legend about a dark winged creature with glowing red eyes allegedly seen in Ukraine in the weeks leading up to Chernobyl Disaster of April 26th 1986. The creature seems to be based on the famous Mothman folklore and a misleading line from the Mothman Prophecies movie that bled over into the Search For The Mothman documentary in 2002.
There is no known evidence in news press or otherwise to show that the supposed witnesses exist or that the story of a bird creature being sighted in Chernobyl is anything other than online fiction derived from a movie line.
In the 2002 film Mothman Prophecies, based on the book of the same title, the character Alexander Leek reads-aloud: "In ancient cultures, the moth represents a form of the psyche, or the soul immortally trapped in the hellish death realms." He then says "Mothman. Well, that's what the Ukrainians called him. Rough translation of course. There were a hundred sightings in Chernobyl the year the nuclear pump went down. Galveston, nineteen sixty-nine, just before the hurricane. They saw it. But seeing isn't always believing."
Not only is Mothman's name NOT Ukrainian, it's based on a newspaper title referencing Batman.There were no reported Mothman sightings in that area before the Chernobyl disaster or before the Galveston hurricanes which occurred in 1900 and 1915, not 1969. The scene was entirely made-up by the screenplay writer Richard Hatem for the film. Despite this, the false "factoids" were repeated in the narration of the 2002 Search For The Mothman documentary which included clips from the movie and was included on the film's DVD release.
The exact origin of the "Blackbird of Chernobyl" story is unknown but the oldest posts of it on the internet seem to trace back to 2005. The story seems like a fleshed-out version of the line from either the Mothman Prophecies movie or the Search For The Mothman documentary in 2002. The author, in the original text, shows knowledge of Mothman-lore by referencing the creature from 1966 but fails to provide any source for how they obtained word on of this Chernobyl "rumor" among the ranks.
The Blackbird story did not originally appear in any known newsprint or publication but it became well known all across the internet as a form of online folklore or "Net-lore". In order for this story to make sense the original author would have had to somehow find this never-before-seen information from Chernobyl 1986 and post it to the internet in the 2000's around the same time the Mothman came into mainstream consciousness with a film containing a line similar to this story. All signs point toward this just being a fictional creepy story inspired by the already established trends of Mothman being an "omen of doom" before tragedies like the Silver Bridge Collapse.
Source(s):  https://www.imdb.com/title/tt0265349/characters/nm0000869#quotes [Movie Line] Mothman Prophecies Motion Picture Screenplay by Richard Hatem (Line 166, Page 80)
In September of 2007, researcher Loren Coleman , who was a consultant on the Mothman Prophecies movie, posted an article on the blog Cryptomundo entitled "Mothman's Fate" in which he said "There are no records of Mothman at Chernobyl or Galveston or before any earthquakes. Since Mothman encounters did not happen in those locations, such unfortunate tales are ones that both [John Keel] and I tried to remove from people’s mental 'databases' as soon as the movie and documentary noted them in 2002."
In 2008, in a posted titled "Galeston Mothman?", he insisted "This is poor myth-making ... The famed big hurricanes in Galveston occurred in 1900 and 1915, long before the Houston Batman was seen in 1953. The movie also tries to link Chernobyl’s nuclear meltdown with precursor sightings of Mothman. Not true. There were no sightings. It was all made up for the movie. Time to move on from these fictionalized additions to the Mothman story that keep distracting researchers from any real investigations of the Point Pleasant phenomena, whatever that might be." He repeated this yet again in April of 2011 with the post "Yes, Chernobyl’s 25th Anniversary But No Mothman Was Seen". In 2012, researcher Micah Hanks wrote an article for Mysterious Universe  listing the supposed Mothman Chernobyl sighting as a misconception within Mothman mythology.
Despite this, the Blackbird story has been mistakenly featured on popular paranormal sites such as "AmericanMonsters" in 2005 and "PhantomsAndMonsters" in 2010. It's also become known as a "CreepyPasta" which is a form of copied and pasted online story that is widely circulated. It was posted on The CreepyPasta Wiki in 2013 , this gained the story a noteworthy amount of popularity and public awareness.
In Tobias Wayland's 2019 book, Lake Michigan Mothman , he quotes Loren Coleman's comments and says "The tragedy at the Silver Bridge is, to date, the only recorded disaster to be associated with Mothman wherein the creature was sighted prior to the unfortunate event; although folkloric account exists saying that Mothman was present at many historical disasters. According to ... Loren Coleman, these later stories are based on events taken from fictional sources". 
Source(s):  [Coleman] https://web.archive.org/web/20170620075853/http://cryptomundo.com/cryptozoo-news/mothman-fate/  [Coleman] https://web.archive.org/web/20191117224444/http://www.cryptomundo.com/cryptozoo-news/galveston-mm/  [Coleman] https://web.archive.org/web/20190531040552/https://cryptomundo.com/cryptozoo-news/chernobyl25/  [Jan 2012, Micah Hanks] https://mysteriousuniverse.org/2012/01/mothy-misconceptions-clearing-the-air-about-the-mothman-mythos/  http://creepypasta.wikia.com/wiki/The_Blackbird_of_Chernobyl [2013 Re-post] [Note: The CreepyPasta Wiki contains fictional writing]  The Lake Michigan Mothman by Tobias Wayland (Page 6-7)
The Story:The following is the commonly repeated online story that is most likely fiction but has gained popularity as internet-lore or "net-lore":
Version One [ Earliest Known 2005 ] :
"Beginning in April of 1986, a rumor tore through the ranks of what was then a little know nuclear power plant located in the southern tier of the Ukraine - Chernobyl. In the days preceding the tragic meltdown, four Chernobyl employees had reported seeing what they claimed was a large, dark, headless man with gigantic wings and fire-red eyes.
Researchers now believe that the accounts surrounding this creature are similar to what investigators now recognize to be an archetypal Mothman event. Much like the Point Pleasant Mothman witnesses, these Chernobyl employees began to share unsettling and strangely similar experiences.
Some had been having horrifying nightmares, while others received threatening phone calls. According to accounts, some of these employees even mentioned their bizarre experiences to their superiors at the facility, but without evidence or any clear cut indication of what the problem may be, there was very little these officials could do - even had they been willing to take action.
On April 26, 1986, during a routine test of Reactor 4, the Chernobyl nuclear power plant was rocked by a massive explosion. Thirty people died that morning, followed by ten additional ten deaths due to radiation exposure. Over the next nine days the graphite of the reactor continued to burn, resulting in tremendous environmental damage and an untold number of radiation casualties over the next 17-years.
As the Soviet helicopters circled the smoldering plant, dropping over 500 pounds of clay, sand, lead, and other extinguishing chemicals on top of the flames, some of the surviving workers - who, at the sacrifice of their own lives, heroically struggled to prevent any further destruction - claimed to have witnessed what has been described as a '20-foot bird' gliding through the undulating tentacles of irradiated smoke, which continued to spew from the reactor."
Source(s):  http://www.americanmonsters.com/monsters/avian/index.php?detail=article&idarticle=219 [2005 Post] Archive April '05 (Highlight) - http://web.archive.org/web/20050410181836/http://www.americanmonsters.com/monsters/ avian/index.php?detail=article&idarticle=219 http://www.unexplained-mysteries.com/forum/topic/72221-mothmans-family/#comment-1236099 [2006 Discussion]
Version Two [ Earliest Known 2007 ] :
"Beginning in early April of 1986, the people in and around the Chernobyl Nuclear Power Plant began to experience a series of strange events revolving around sightings of a mysterious creature described as a large, dark, and mutated man with gigantic wings and piercing red eyes. People affected by this phenomena experienced horrific nightmares, threatening phone calls and first hand encounters with the winged beast which became known as the Blackbird of Chernobyl.
Reports of these strange happening continued to increase until the morning of April 26, 1986, when at 1:23 am, reactor 4 of the Chernobyl Nuclear Power Plant suffered a catastrophic steam explosion that resulted in a fire, which caused a series of additional explosions followed by a nuclear meltdown. The power plant, located near Pripyat, Ukraine, then part of the Soviet Union, spewed a plume of radioactive fallout which drifted over parts of the Western Soviet Union, Eastern and Western Europe, Scandinavia, the UK, Ireland and eastern North America. Large areas of Ukraine, Belarus and Russia were badly contaminated, resulting in the evacuation and resettlement of over 336,000 people. The Chernobyl Disaster, as the incident was dubbed, is considered the worst accident ever in the history of nuclear power.
Following the meltdown, and subsequent explosions and fires, Soviet helicopters were dispatched to the scene, equipped with special fire fighting gear, these helicopters circled the plant dropping clay, sand, lead and other extinguishing chemicals on to the burning facility. Most of the fire was put out by 5 am with the fire burning with in reactor 4 continuing to blaze for several hours after. The firefighters who responded were unaware of the nature of the fire, assuming that it was simply an electrical fire, and received massive overdoses of radiation leading to many of their deaths, including Lieutenant Vladimir Pravik, who died on May 9, 1986.The workers who survived the initial blast and fire, that would later die of radiation poisoning, claimed to have witnessed what has been described as a large black, bird like creature, with a 20 foot wingspan, gliding through the swirling plumes of irradiated smoke pouring from the reactor. No further sightings of the Blackbird of Chernobyl were reported after the Chernobyl Disaster, leaving researchers to speculate just what haunted the workers of the plant during the days leading up to the disaster.
The most commonly accepted theory suggests that the Black Bird of Chernobyl may have been the same creature spotted in Point Pleasant, West Virginia leading up to the collapse of the Silver Bridge on December 15, 1968 [sic, Note: 67* not 68]. Investigators have suggested that the appearance of this creature is an omen of disasters to come in the area in which it shows itself. The physical description of both the Black Bird of Chernobyl and the Mothman, the creature sighted in West Virginia, are very similar, and the reports of nightmares and threatening phone calls leading up to these disasters are shared in both cases.
A second, less accepted theory, suggests that the Black Bird of Chernobyl was nothing more than the misidentification of the black stork, an endangered species endemic to southern Eurasia. The black stork stands nearly 3 feet tall and has a wing span of nearly 6 feet. This theory however fails to take into account the menacing phone calls and the the disturbing nightmares. Also the physical description given by the majority of eyewitnesses who actually saw the Black Bird of Chernobyl does not in anyway match the physical appearance of the Black Stork."
Source(s):  Unknownexplorers . com/blackbirdofchernobyl.php - Broken Link [2007 Post] Archive - https://web.archive.org/web/20071130065607/http://www.unknownexplorers.com/blackbirdofchernobyl.php  http://www.phantomsandmonsters.com/2010/05/chernobyls-harbinger-of-catastrophe.html [2010 Re-post] Archive - https://web.archive.org/web/20131212051159/https://www.phantomsandmonsters.com/2010/05/chernobyls-harbinger-of-catastrophe.html