This card was released as a promotional card in the year 2000. It was given out with the purchase of a ticket for the theatrical run of The Power of One in the United States and other countries worldwide at participating cinemas within the first week of release. After the first week of the theatrical run, attendees would only be able to receive a Moltres, Articuno, or Zapdos. This version came sealed in a plastic wrapper together with a teaser card for the Pokémon League.
The Japanese version was included in The Power of One movie pamphlets available to purchase at participating cinemas from July 17, 1999 for as long as stocks lasted. The first Japanese prints of the card featured a speckle Holofoil treatment and misspelled Nintendo in the copyright text on the card border as "Nintedo". A corrected print was released for a very brief time with the same Holofoil as the first print. Then, after the corrected version, a third version was released featuring the same Cosmos Holofoil treatment as the international release. Although subtle, there are differences between the third Japanese print and the international print: the copyright information of the international print is in a different font to the Japanese print and has an additional Wizards copyright. The border pattern on the international print is more pronounced than the Japanese print and does not extend to the card edge due to the wider border.
As an homage to the original released twenty years prior, a fourth Japanese print was included in Mewtwo Strikes Back—Evolution pamphlets available to purchase at participating cinemas from July 12, 2019 for as long as stocks lasted. This print has the speckle Holofoil treatment and a 2019 copyright.
This card's text is depicted in medieval Futhark Runic and Gothenburg Runic writing; this page uses their English equivalents. People who attended a Wizards of the Coast event were given a sheet to read the runes. Based on this cheat sheet, the runes in the middle translate as New Species while the ones on the bottom translate as Little Cat... or Evil?. Four symbols in the Holofoil printing behind Mew were said to stand for Birth, Enthronement, Right of Succession and Death. A method to decrypt the runes was also published on Pokémon.com, which referenced several other cards to determine what the card says. Due to this card's text being in Runic, this card is one of only two cards to have ever been banned from the Unlimited format in addition to the Standard format. It shares this distinction with _____'s Pikachu. The card's illustrator is also unknown due to the unusual design.
This card was depicted in The Power of One as the object that started Lawrence III's collection. The card was the only object from his collection still in his possession at the end of the movie. This was the second appearance of a TCG card in the anime, after the depiction of Dark Primeape in the Japanese version of EP073. No more TCG cards would appear in the anime until Pearls are a Spoink's Best Friend. In addition, the English dub had Lawrence III explicitly attributing the card as the start of his collection, in order to better tie in with the ending, as the pamphlet was not available with the American release.
The Weakness and Resistance symbols for Ancient Mew can be seen on the Xatu totem pole on the cover of the Neo Premium File 2.
Following the 2019 reprint of the card in Japan, that print and all prior prints became permitted to use in the Japanese Standard format starting July 26, 2019. Players using the card in sanctioned events were required to have a printed copy of the official card database entry detailing its text and place their deck in sleeves to make the card reverse indistinguishable from others.