Bosley Bookworm is a very efficient assistant, despite lack of limbs: he can perform various actions, among them finding the books Blueberry needs, throwing items to their correct place and answering the telephone.
Bosley never complains about Blueberry's whims, like when she reads nonstop Patty Persimmon books and does not let him sleep, or when he is hit by a book.
Sometimes Bosley has a good advice for Blueberry:
- On "No Blueberry is an Island", Blueberry tells him about the problem she got herself into. He advises her to tell her friends the truth, what she eventually does after Strawberry persuades her.
- On "The Big Freeze", he advises Blueberry to use ice skates for reaching Berry Bitty Dale, where she can obtain the book she is waiting for. The advice, combined with the old tennis racket that Bosley got stuck in due to the strong wind, give her the idea of Icy Skites. Later, Blueberry is unsure whether she can make the commercial of the Icy Skites, and Bosley encourages her to go for it. He also suggests that she ask her friends to help her, and she does.
- On "The Mystery of the Disappearing Dog Show", as Blueberry and Huckleberry run out of ideas, he advises them to write about what they know. They follow his advice, and their story is accepted.
Bosley Bookworm's skin is colored with pale and dark green stripes and white dots. He has a broad nose, beady eyes and dark green eyebrows. He wears blue glasses with large trapeze lenses.
- "You never know what you might be good at, until you try."
- "If you would welcome a suggestion, I've always liked the advice: write what you know."
- On "Berry Bitty World Record", Bosley surprises everyone by revealing that he is the contest judge sent by Berry Bitty World Traveler magazine.
- Bosley is the only Bookworm with speaking lines on the show. On "Top Talent", Bookworm Bob and his cousins Bart and Boris make appearance as the judges of the contest, but they have no lines.