The story
From Morbius (character from Marvel Comics; also, the title of a 2022 film featuring said character) + -illion (numeral suffix for powers of 1000). Alternatively, from a blend of Morbius + billion. Due to the film's critical and commercial failure, Morbius became the subject of Internet memes claiming that it was "the first movie to make over one morbillion dollars".
Etymology from Wiktionary, CC BY-SA 4.0.