It began as a joke but, in the greater context of the Babadook himself, LGBT history and so-called gay icons, it actually makes sense.
"Someone was like, 'How could "The Babadook" become a gay film,' and the answer was readily available," said Karen Tongson, an associate professor of gender studies and English at USC. "He lives in a basement, he's weird and flamboyant, he's living adjacently to a single mother in this kind of queer kinship structure."
LA Times, June 2017
The meme drew its most attention when June, LGBT Pride Month, began. Then, the jokes about Babadook's gay identity spread with such fervor they were covered by Mashable and Teen Vogue.