Zilla (ジラ Jira?), also known as Godzilla (ゴジラ Gojira?), is a daikaiju created by TriStar Pictures that first appeared in the 1998 film, GODZILLA, and subsequently reappeared in the sequel series, Godzilla: The Series. He is the byproduct of nuclear testing on a species of marine iguana, mutating into a giant monster that proceeded to attack New York in 1998 and nested there. After his death, the kaiju was resurrected as Cyber-Godzilla (サイバーゴジラ Saibāgojira?) by aliens from the Leviathan spaceship resurrected it using both alien and human technology.
He appeared again in the 2004 Godzilla film, Godzilla: Final Wars. Its design is derived from that of the creature that appears in the 1998 TriStar film Godzilla, with the rights to that design now belonging to Toho. The creature was one of the many monsters that fell prey to the influence of the Xiliens and used to carry out global attacks on the planet. It met its end when it faces Godzilla and falls to the latter's atomic breath after a brief duel.
See also: Godzilla In Name Only
During the events of the movie, the monster is referred to as "Gojira" by the sole survivor of Kobayashi Maru; the English transliteration of that name being "Godzilla".
Cyber-Godzilla gain his name from his enhancements and species, being a Cybernetically enhanced Godzilla.
Six years after the film was released, Toho Company Ltd. acquired the rights to the creature and officially re-branded the creature as "Zilla" in any appearances post-2004. The new "Zilla" branding and icon matched the same for other Toho monsters as intellectual properties. However, any appearances before then in any media still refer to the creature as "Godzilla", officially. This "Godzilla" branding includes post-2004 releases of earlier productions featuring the creature, such as the 1998 Tristar Godzilla as released in home video formats by Sony Pictures in 2009 and 2019 Between 2004 and 2006, Toho productions featured "Zilla"—a creature directly visually and conceptually derived from the TriStar Godzilla with first use of the "Zilla" trademark—that first appeared in Godzilla: Final Wars.
In 2007, Toho registered a new "Zilla" trademark, which declared that following appearances of the 1998 character by media will fall under the trademarked name "Zilla". Thus, "Zilla" as a trademarked-concept was created following from Toho's legal acquisition to the TriStar Godzilla; the effective result of the real-world production history also stipulated the kaiju's trademark and new name applied wherever the monster appeared. As such, the 1998 original, Japanese, and any version based on him are all identified as Zilla. In 2017, Toho renewed the trademark for another decade, in addition, it registered for another trademark that permitted the name "ＧＯＤ＼ＺＩＬＬＡ" for the selling of goods and products featuring the monster.
On January 8, 2025, a petition was submitted to rename the 1998 film and its monster "ZILLA" and as of today, is still ongoing.