Filbert is a male, anthropomorphic squirrel employed as head doctor of the Metal Glen research facility.
Filbert was a slow-witted,and shy squirrel. He also loved the smell and taste of Apple's cordial.
Filbert is the mascot of The Royal Academy. Filbert is a hedgehog that lives in a fenced area and is taken care of by the students and the headmistress. When he runs away, Travis helps you and Summer find him. Summer's guess is that he is always running away because of Chaz's Gyro Dance Ball. Summer and Travis want you to decorate his fenced area and herd Filbert back into it. Summer thinks that Filbert makes a great mascot but, Liberty thinks a snake would be a better mascot than Filbert.
During Guybrush Threepwood's search for Big Whoop, Filbert successfully caught him as he was trying to get away with map piece belonging to the Governor. It is unknown why, but he resigned from his duties at the mansion a short time afterwards.
Filbert (voiced by Howard Morris) is a worm from U.S. Acres that Booker often chases, but with no success. He lives in a hole with his wife and son. He appeared in the animated series, but he was never named on the show.