The idea of extraterrestrial humanoid enemies was first conceived by Shōji Kawamori, inspired by the trend of militaristic alien antagonists from previous science fiction shows like Space Battleship Yamato (1974).

[3][4] They contributed greatly to the expansion of the Protoculture Civilization's sphere of influence and the creation of an "Interstellar Republic" (akin to a galactic empire) that controlled most of the Milky Way.

[1][5][6] As war broke out with The Supervision Army centuries later, the Zentradi entered into combat with their fearsomely powerful force of millions of space warships and mecha produced in thousands of huge automated factories scattered across the galaxy and legions of expendable giant clone troops.

[9] It seems that no Zentradi were trained in the repair and maintenance of their equipment, making them dependent on easily controlled supply stations and factory asteroids.

[11] In the first Macross TV series it was revealed that Commander Type Zentradi are bigger, stronger and more intelligent than the rest, while some are even able to survive in the vacuum of space for limited amounts of time.

[1][9][11][14] In the original Macross TV series the Zentradi possessed a fictional alien alphabet which was developed by Kazutaka Miyatake of the Studio Nue staff but their dialogue was automatically translated into Japanese language.

animated film, the Zentradi were actually shown speaking a fictional extraterrestrial language (that also was developed for the movie by the Studio Nue production staff) as subtitles were provided for the audience.

[25][26] In the Macross setting, Meltlandi or Meltlan is the term for female Zentradi, a giant humanoid alien warrior race segregated by gender.

The spelling and pronunciation of these terms is difficult to interpret, as the Japanese language uses a series of characters that split the difference, phonetically, between the English letters "L" and "R", and thus can be transliterated as either.

In the American adaptation of the series (Harmony Gold, 1985) the Zentraedi were originally a genetically engineered race of giant clones that served the people of the habitable moon Tirol from their inhospitable mother planet Fantoma.

Additionally, in Robotech continuity, the near-totality of Zentraedi in existence is found between Dolza's Main Fleet of 4.8 million warships destroyed by the SDF-1, the unified forces of Breetai and Azonia that fight alongside the SDF-1, and one additional substantive fleet led by Commander Reno and tasked with protecting the Robotech Factory Satellite.

Brian Clamp and Julie Davis describe the Zentradi as "a parody of tendencies in human civilisation" and compare them to the Laputans from Gulliver's Travels.