While Tazza never says a word, he's always there, sniffing things and being taken for walks. He also occupies a special place in this Darwinist world of animals that are created for certain purposes. As Dr. Barlow explains:
"Tazza isn't fabricated, and he isn't for anything. Except that I hate traveling without him." (16.33)
In other words, though Tazza might look fierce, he's pretty much there for companionship and love—in short, he's a pet. Tazza serves as a reminder that animals, fabricated or not, are beings in their own right, and his presence invites us to consider how animals are treated in Darwinist society.