Tweezel was a spindlebug and the inventor of the varnish that made the Second Age of Flight possible. Tweezel was one of the few spindlebugs known to live outside a Gyle Goblin colony. He lived for centuries, appearing in the Quint and the Rook trilogies and having seen three Ages of Flight. He was known to be very devoted to his work. Later on, Tweezel moved to the Free Glades. In the short story The Sky Chart, he was the narrator.
Tweezel hatched and lived in a Deepwoods Gyle Goblin colony when he was young. However, a group of slavers came and destroyed the colony, enslaving or killing all of his fellow Spindlebugs. Tweezel escaped and set out for Undertown, in hopes of a new beginning. He did make it to Undertown, but he had no money and could not support himself. Earth-Scholarship was still respected at that time, and the High Librarian found him starving in a run-down section of Undertown, bringing him up to the then Palace of Lights. He was appointed caretaker of the palace, and so he methodically tended the building with love and care, even when it fell into darkness and became the Palace of Shadows after Earth-Studies fell out of favour. He lived alone in the palace for decades, until the new Most High Academe, Linius Pallitax, moved into the palace 60 years later. At first, Tweezel didn't trust Linius enough to reveal himself, but gradually he discovered Linius respected Earth-Studies. He continued to tend the palace until it was burned down by the Gloamglozer. Tweezel rescued Linius from the inferno, but the Most High Academe died soon after. Upon Linius's death, Heft Vespius had a forgery of the High Academe's will created, and came into ownership of all of his property and employees. Heft swiftly fired Tweezel, but he remained in Undertown along with Welma, seizing every opportunity to check on Maris.
Many years later Maris set off for the Deepwoods in search of her long-lost son, Twig, and Tweezel accompanied her. The pair of them discovered and settled the Free Glades, and began their lives anew. Tweezel oversaw the construction of the Gardens of Light and invented a special varnish which made possible the Second Age of Flight. He supplied this varnish to the Librarians Academic, who used it to construct a fleet of skycraft. He also befriended Xanth Filatine and helped him through the guilt he felt over his past.
Tweezel was quite clever, and very devoted to his master. He once saved Linius Pallitax from a pair of would-be assassins, Bagswill and Seftus Leprix, who attempted to murder the High Academe with a bottle of poisoned sapwine. He examined it, found out that it was poisoned, and retaliated by re-gifting the bottle to Seftus Leprix's unwitting servant, Jervis. Jervis gave the poisoned sapwine back to Seftus Leprix. Not knowing that it was the same sapwine, Seftus and Bagswill drank it in a celebration that Linius was "dead" and died exceedingly painful deaths from their own poison. At another point in time, he carried Linius's unconscious body out of the burning Palace of Shadows. Tweezel was shown to be proud of his work and had the stuffy personality of a butler. During the Quint and Rook trilogies, he was very old and slow.