Unk is a pit guardian at St. Aegolius Academy for Orphaned Owls. He is a male Great Horned Owl, or Bubo virginianus, and was Gylfie's pit guardian when she was taken to St. Aggie's. He would insist that Gylfie would call him by the name "Unk," short for "Uncle," which is almost identical to the way which Finny would insist that Soren would call her "Auntie." Unk would occasionally give Gylfie extra pieces of snake and would call her by her real name, instead of her number designation, 25-2. He also allowed Gylfie to sleep during daytime, and was most likely killed by the Pure Ones when they conquered St. Aegolius.
When the Chaw of Chaws arrived at St. Aegolius on a secret mission sent by the parliament of The Great Ga' Hoole Tree, Unk was seen as some sort of interrogator.