Archie (species)
From Tardis Wiki, the free Doctor Who reference
Archies were alien lifeforms that lived in pairs, one inside the other. When they became separated they could cause great chaos. On Earth an Archie adopted the form of a school boy to study and learn about Earth. But when the two became separated as a result of a sneeze, the school and streets of Leeds became covered in snot, with a giant snot monster on the loose. The Eleventh Doctor reduced the snot monster in size and returned it to Archie's nose, reuniting the Archies. (COMIC: The Runaway Bogey)