A talking tree creature from the children's holodeck stories The Adventures of Flotter, who lives in the Forest of Forever and is one of Naomi Wildman's favourite playmates aboard Voyager.
Trevis appears in the fifth-season Voyager episode Once Upon a Time, played by Justin Louis. He is a holographic character in The Adventures of Flotter, a series of educational holonovels for children, and is the cautious, rather fretful companion of the water creature Flotter.
Naomi Wildman plays the stories with Neelix while her mother Samantha is missing on a crashed Delta Flyer. In the tale she runs, Trevis and Flotter squabble over the forest and are then threatened by the Ogre of Fire, who burns the trees and boils Flotter away, leaving Naomi to work out with Trevis how to bring him back.
Several of the adult crew remember the characters fondly from their own childhoods, and the stories give Naomi somewhere to retreat when she learns the truth about her mother.