18.

Not only are Turkey, Nippers, and Gingernut character foils for Bartleby in the workplace, they also seem to be satirical characters made for Melville's amusement. For example, his descriptions of Turkey and Nippers seem like descriptions of people he knows, only carried to the next level of mockery. Turkey's alcohol problem and Nipper's neurotic, meaningless rages seem like character traits he has personally experienced in coworkers.
However, as interesting as Turkey, Nippers, and Gingernut are, and as much as they add to the tension of the office, I felt like they didn't seem any more real than Bartleby. Each was such an absurd or trivial character sketch, they almost seemed more ridiculous than meaningful.