It's an aggressively homosexualaboriginal that attacks you (in the binung) while you are unconscious. The nightmares that follow is what they call the Dreamtime. You may encounter it during a coroboree.
Person 1 : are you OK?
Person 2 : I feel fucked after last night's party.
Person 1 : probably that Rainbow Serpentmate, now you understand the dreamtime.
Boys who enjoy yaoi (a genre in Japan that contains sexual and/or romantic relations between two men); literally translates to "rotten boy"; corresponding female : fujoshi