Over the years I've seen a small collection of fake-names crop up in the sysadmin space. Here is a list:
BOFH
An oldie, but a Sysadmin who has gone over to the dark-side.
Fred
Originally coined by Laura Chappell, Fred is the User From Hell. Or, The Power User who Isn't. Fred knows everything, or rather, thinks they do. They're wrong, but don't know it, and it makes your life all too interesting. Fred may be a manager, a peer, or a frequent-flier in the ticket queue.
Leeroy
Originally from a famous Warcraft video, this is the peer who just deploys stuff because it's cool. They... haven't learned (the hard way) how this can go wrong, so aren't naturally suspicious. This could be the rose-colored glasses of youth and exuberance, or it could be a trusting nature. They'll learn.
Brent
Coined by The Phoenix Project, Brent is the person that ends up with their hands in everything one way or the other. They may be a single-point-of-knowledge, the only person who knows anything about topic X, or just the person that gets handed the weird stuff because, well, "Brent probably knows". A lot of us are a Brent, and it sure as heck makes getting long vacations approved difficult. There may be more than one of them, depending on topics.
I used to be a Leeroy, then I learned better.
I've been a Brent (oddball-stuff troubleshooter variety) at my current and last three jobs.
Right now people have figured out that I know how to use Wireshark to discover oddball problems, so I'm having to do a lot of packet analysis lately to rule out oddball problems. This isn't something I can cross-train on very well, but I'm going to have to find a way; people's eyes tend to glaze over when you get into TCP RFCs and it's easier to make me do it and not have to learn for themselves.