Drokkvid was a carnivorous alien from an unknown place. When Miss Brayley found the Drokkvid in her plants, she thought it was hurt, so she gave it lunch, accidentally making it become a giant creature, that eats a lot! (COMIC: Teacher's Pet).
History
A biology teacher find this Drokkvid in some plants, outside her classroom, prepering for the next class. She gives it food, which would later become a giant creature, instead of something small and cute. Children and staff find out there is a lot of food missing from everywhere. The Eleventh Doctor and Clara Oswald start looking for it. They enter Role Hill School, and search for it. In the end, it's shrunk into it's normal sized body. (COMIC: Teacher's Pet).