As all principals of any educational institute, Bump is responsible for the care and maintenance of Hexside as well as the safety and well-being of his students. While he is of a stern and intimidating visage, he takes his responsibilities toward his students seriously and genuinely cares for their success within and beyond Hexside.
Principal Bump is an elderly man with light beige skin and teal eyes. He wears what appears to be a demon-like hat that covers up half of his face and traditional academic dress consisting of a long black gown with a gold yoke with black cape, gold trim at the sleeves and a blue stole.
- "Hieronymus" comes from the painter Hieronymus Bosch whose art style set the aesthetic for The Owl House.