The comic "It's Square To Be Hip" opens with Quint and Julia looking at a poster of teen singing sensation Jimmy Zoopie-Doo. Harvey asks if it's Justin Bieber, and Julia points to an actual poster of Justin Bieber... and it's a photo of a toddler, with a girl swooning.
While running away from Michelle in "The Wizard II: Fax Me an Angel!", the protagonists encounter someone resembling Death.note It's actually Jenny Lewis wearing a dark cloak. After this person asks them to run away in fear, Harvey retorts, "This time, you're the lesser of two evils!"