— Justice Rookwood, Ravenclaw —
Erklings are a type of dark magical creature, most notably because of their affinity for not just human flesh, but the flesh of human children. It would, perhaps, not be as dire if the creatures hailed from a habitat far away from human civilization; however, on numerous occasions, erklings have been discovered in the Dark Forest outside of Hogwarts!

In their attempts to secure meals, the erklings will lure small children away from their parents or guardians, and may even take to shooting darts at unsuspecting passersby. If they so desire, they could even attempt to charm their victims with human speech, for erklings are gifted with the unusual ability of human speech.

Many have pondered the possibility of house-elves being a more benevolent, contemporary version of erklings bred specifically to suit the needs of wizardkind, but some academics have disputed this theory.

A notable variation of the erklings are the "Bavarian erklings", which are said to far nastier and much more vicious than even English erklings. English erklings, however, are classified as XXXX by the Department for Regulation and Control of Magical Creatures, meaning the Bavarian variety must be particularly violent creatures.