Drutt is a grey, blob-shaped bug that appears in The Trap Door. He is Berk's irritating and useless pet and does little around the castle other than chase and gobble down worms and get in Berk's way when he's busy. He constantly makes strange squeaking noises which tend to grate on Berk's nerves.
In later episodes of The Trap Door, Drutt is shown to have a family. His babies - which Berk calls "nippers" - are just as irritating and stupid as Drutt himself.
Drutt feeds his young with same worms he uses to gorge himself, often causing trouble for other occupants of the castle while doing so. Babies receive their meal enthusiastically and speak (or at least make some noise) with even higher pitched squeaks than their father.
- Although Drutt is always regarded as a "he", he has a clutch of babies but has no mate. This could mean that Drutt is parthenogenetic, though such questions are not raised in a children's television show.