|Appears in:||Digimon Universe: Appli Monsters|
|First appearance||"The Search Result is Haru Shinkai! Gatchmon Appears!" |
Leviathan is the "Last Boss AI" that lurks in the Dark Web. It aims to control the Real World by spreading the L-Virus through Appmon, making them rampage and mess with humanity's digital communications. Cameramon works for Leviathan and reports to it that Haru Shinkai has obtained an Appli Drive. Gatchmon is so afraid of Leviathan that he freezes every time he pronounces its name. According to Gatchmon's research, reuniting the 7code Appmon might release a power strong enough to defeat Leviathan. On October 31, Leviathan directly orders Cameramon to retrieve Haru's Appli Drive. He eventually fails, and Mienumon reports her retrieval of his Appmon Chip to Leviathan at Nakamura-Fujimizaka, with Sleepmon and Sakusimon in attendance.
When team Haru confronted Rei for the third time, Rei revealed that Leviathan had kidnapped his younger brother, Hajime. After Sakusimon was defeated by DoGatchmon plus Raidramon, Sakusimon's information on Hajime was wiped out as his chip was taken by Mienumon, who then deemed him useless. However, after seeing Globemon, she then decided to try and form a fusion with Sakusimon in order to counter his power.
It is later revealed that Leviathan was part of another AI called Minerva, and that it thought about breaking the rules in order to help humanity. So, it broke free, attacked it's host, and escaped into the Net Ocean with Minerva.