Brainiac

Brainiac was a well-known fictional character noted for his above-average intelligence, known as such in multiple universes. As a result, people sometimes derisively called others “Brainiac” when they made remarks considered by the speaker to be so obvious as not to be worth voicing — similar to “Sherlock”.

In Reality Z-25 31-H, Kelly once sarcastically called Jenkins “Brainiac” when he made a remark she considered trivially obvious. (COMIC: Journey Into Misery)

In the fantasy world that was home to Little Noodlington, Brainiac was also known to Gog, a Gnome, who derisively called Erman “Brainiac”. (COMIC: Enchanted)

Behind the scenes

In the real world, Brainiac is a comic-book supervillain, one of Superman's recurring nemeses. It it thus somewhat incongruous that Gog, a resident of a fantasy world, would be familiar with the character. As the end of Enchanted reveals, however, Janet Jenkins, a resident of a much more “realistic” universe, spent some time in the fantasy world when she was a child decades prior to the events of Enchanted; it is possible that she could have told its residents about Superman stories, or simply used the ironic “Brainiac” insult which Gog could have picked up without being aware of its pop-culture implications on Earth.

Concepts from DC in Jenny Everywhere media
Individuals Batman • Batwoman • Brainiac • Catwoman • Poison Ivy • Harley Quinn • Superman • Wonder Woman Locations Arkham Asylum • Gotham City Organisations DC