Yogi Bear is shown in the background (restrained to a hand truck like Hannibal Lecter) as an inmate in the Animal Asylum for the Criminally Insane.
The Crystal Cove's Animal Asylum for the Criminally Insane is an obvious parody to infamous Arkham Asylum, a mental institution and a prison, where most of Batman's enemies are incarcerated.
The theme that plays throughout the episode is the same theme from the Terminator movies