Thread:5000 Explosions and a Supernova/@comment-25499471-20141112175830/@comment-4604636-20141114005706

I agree that it looks like Marina.

I can only think of two other instances where a character appeared due to an error:
 * Maria is briefly replaced with Nancy in Germophobia.
 * Binky is in Mr. Marco's class in the flashback episode Arthur and the True Francine.

Neither Nancy nor Binky have very complete appearance lists yet, so it is not on either of their pages.