My officemate and I call our senior manager “rapid feet” because of his fast walking style when he walks down the hall and approaches someone’s office.
All supervisors are “Bobs”, as in Office Space.
I gave one of my bosses the choice between Big Bird and Silver Sable. She chose Silver Sable. Our VP asked me what nickname I had for him and I just said, “Mr. VP, sir.”
Years ago a contractor whose name was Richard was engaged to run a unit, the SAU. He was spectacularly bad and was soon known as “Dick, head of the SAU.”
At the moment we have a BS artist who has climbed the ladder to be a director despite his endless string of failures. He is commonly referred to as “Teflon Nick.”
Usually “The guy I’m about to strangle”
We had a father and son in different but adjacent parts of the company, and their names were identical except that one had an extra middle name, because of which they didn’t use Senior and Junior. We called them “… the Elder” and “… the Lesser”. This latter nickname was especially nice because he was a real climber, a real power hog.
I had nicknames for a very small subset of co-workers, usually driven by some unpleasant encounter. “Captain Obvious” was one example, “Not Me” was another.
At one job I had two guys named Bob. I referred to the black guy as “Bob” and the white guy as “Tubob”, which is Bambara for “white person” and also sounds like “Bob No.2”
The boss there was usually referred to by humming the theme music for Miss Gulch in The Wizard of Oz.
In the Navy, there were all manner of Ensign Thimbledick, LT Numbnuts, etc.
We had an 3D artist we worked with, who was a great artist, but somewhat obsessive, like we had a few weeks to work on a demo of car driving down a street and he would do stuff like spend a week building a perfect photo-realistic tree stump.
We called him Hans Kubrick after the obsessive film director (and because he was called Hans 
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Last year I hired an engineer. She was very fiery and flirtatious. My coworker and I were cautious with our interactions with her, and called her “hot potato.” She is no longer employed with us due to inappropriate behaviors on her part.
I do for my students, does that count? Not to be disparaging in any way towards them, but simply because I’m kind of lousy at face recognition and need to use secret cues for myself to link a personal appearance to a name.
Mostly they involve associating the student with a fictional character with a similar name, whose appearance as shown on film or described in a book reminds me of the student.
We sort of did. She was called the ‘Mumbler’ because she would not speak up so that people could hear her.
20 people in a meeting and mumble mumble mumble Yes, I am hard of hearing. I have hearing aids for that. I fixed it.
But nobody can hear her.
I like her, I do. But sheeeesse. Enunciate would ya please. A lot of people do this. Look down at their notes and mumble.
“WE, THE PEOPLE OF ROCK RIDGE” Is what you should do in a setting of many people in a large room.
All in all we all get along great. Working from home has helped us all out. We much prefer the written word.
I used to work with Professor Smartypants. He was always the smartest person in the room, and his software designs were always the best way to do anything, because if there were a better way, he would have thought of that first because he’s so damn smart. “Professor” because he moonlighted teaching at a local coding boot camp. Fortunately he left and took his underappreciated brilliance elsewhere.
Years ago we had a new VP of our division who, I swear, looked like he was fresh out of high school. My comment was “that’s like making Doogie Howser the chief of surgery!” So his nickname became “Doogie”.
One of the managers is just known as the “Short Man”.
Not only is he on the short side, but his immediate boss, plus her boss, happen to be tall women.
I work with my brother-in-law, I call him Cousin Eddie. He’s holding out for a management position.
Someone I know is an editor and grants writer working with medical researchers to help them write up their grant applications, research papers, etc. Her least favorite collaborator is the so-called “Dr. Procrastinator”, who is always massively late with everything.
I’ve never interacted or been introduced to a young co-worker, a short, Hispanic woman with large glasses and long curly hair. So in my mind, I call her “Mirabel”, after the protagonist of Encanto.
We used to have two Carl/Karls in our small workgroup, so they became Cee-Carl and Kay-Karl.
This isn’t about nicknames, but they needed some! Two identical twins worked in the same department, and their names were Roland and Ronald. I’d not only confuse them for their looks, but my eyes would often confuse their written names.
Co-worker across the hall from me. I call her Mary Poppins. Sing-song-y voice. Happy happy happy all the time. Covid, happy. January 6th, happy. Her brother died, happy. And I don’t think it is drug related. It’s like her needle is just stuck on happy.