Filbert served as the gardener of the Elaine's Booty Island mansion.
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. When Guybrush tried to run away, Filbert threw his rake in front of him which knocked Guybrush out as it knocked him in the face. He took the pirate to Elaine as well as giving her back the map piece. After briefly listening to their conversation he went to rake the backside of the mansion.
It is unknown why, but he resigned from his duties at the mansion a short time afterwards.