Alien Alien (エイリアンエイリアン) is the 12th cover by Hello, Happy World!, and was originally sung by Hatsune Miku.
It was first announced on August 21, 2018, and released in the Japanese official Bang Dream Game server the same year, and also available in all the other servers.
A full version of the cover was later released on NicoNico and inserted in the album Girls Band Party! Cover Collection Vol.3, released on December 12, 2019.