There are a few other characters worth a quick mention, like Ricky, the office boy who is the best example, actually, of what it's like to join fight club. He's one of the first members, and the very first person to show up to apply for Project Mayhem. He works a thankless job and Project Mayhem and fight club are the only way he can feel important.
There's also the Mechanic, who doesn't have a name but has plenty of speaking lines. It's he who starts the "His name was Robert Paulson" chant.
Two other men don't join fight club, but get a scene apiece. One is Lou, the own of Lou's Tavern. Very creative, Lou. He tries to stop fight club, and beats Tyler senseless in the process. But Tyler lets him, and this masochistic craziness frightens Lou more than any violent act ever could, and he lets fight club stay in the basement of his bar.
Finally, there's Raymond K. Hessel, one of the characters with a full name. Tyler drags him from the convenience store he works and threatens to kill him and then lets him go saying, "If you're not on your way to becoming a veterinarian in six weeks, you will be dead." See, being a veterinarian is Raymond's dream, but, having been beaten down by society, he ended up working a dead-end (literally) job.
Our narrator is appalled at how Tyler threatens Raymond, but then he realizes that Tyler has a point. After he lets poor Ray run home to start vet school applications, Tyler says, "Tomorrow will be the most beautiful day of Raymond K. Hessel's life."