The story
A popular term used notably by Dr. Heinz Doofenshmirtz, a character from the 2007 American animated television series Phineas and Ferb; however, usage dates to at least the early 2000s, e.g., kupkake-inator in the 2003 film The Cat in the Hat. Modelled after Latinate agent nouns such as terminator. See -ator.
Etymology from Wiktionary, CC BY-SA 4.0.