This is a good question! And the answer is: I think the community made up the 'Fritz' part. Pretty sure that's what his name is in Emesis Blue (which is, incidentally, the video that reached up from my Recommended list and violently dragged me back into this fandom, hahah).
But as far as I know, the only name we know canonically is 'Ludwig,' and we're not sure if it's his first or his last name.
This sign is featured in the Man vs. Machine map 'Rottenburg.'
According to the wiki, this is a blurb from the official update that included this map:
"The second of our Two Cities finds the mercs defending the Medic's vaguely European hometown of Rottenburg — a sprawling village famous for its centuries-old traditions of 1) chasing the next in the resident lineage of mad doctors out of town with torches and pitchforks whenever they swapped out too many super-charged baboon hearts,"
Now, this is just conjecture, but this implies two things:
- Ludwig is his first name, and his last name is Humboldt
- HIS ENTIRE FAMILY LINE IS LIKE THIS
Of course, it's also possible that he was unrelated to whatever local mad scientist there was when he was a kid, but he decided 'hey, I'd like to do that too' and then grew up to eventually take over the pharmacy for himself. There are plenty of mom-and-pop type places that are operated by someone whose last name isn't actually on the sign.
So until Valve says something, we don't really know what his last name is - this is just an extremely strong hint.
For the purpose of this blog, though, his name is Dr. Ludwig Humboldt. I haven't yet decided what Misha's last name is.
Speaking of Misha... apropos of nothing, but here's a shot from the supply room in the same map.
(Hahaha floating syringe. Why is it floating? Because players aren't supposed to be able to look at this room from this angle. When viewed from above, you don't notice it's floating.)
Anyway, I saw someone else once point out that our boy Ludwig is fucking obsessed with making diagrams of Misha. He studies him like he's the perfect specimen.
What's that? You want a close up of the diagram? Of course!
"This is the ideal male body. You may not like it, but this is what peak performance looks like." -- Ludwig, probably
Anyway, as you can see, we unfortunately can't read the text when we zoom in. But I do have to note that it is hilarious that the ammo pouches and bandolier are part of the diagram, as if they're an essential part of his anatomy. That is also literally just an A-posed model they loaded in and slapped a skeleton on top of.
I choose to believe Ludwig made this diagram in Blender himself.