My brother linked me a video about the new Monster Hunter Iceborn to translate a joke but I didn’t quite understand it.
The closest that I came to was この親父(がど)お疲れます as something like “this old man did enough for today” then the other guy said…Niceborne! So an old man was able to give birth to a child?
Well the question was about a joke that can’t be translated. So if nobody can translate it, it’s not strange at all
Probably just a pun with Iceborn, adding an N as prefix to make it Niceborn. おつかれ is often used to say “Good job!” or “Nicely done!” There’s probably no deeper meaning to a joke that somebody made up in 2 seconds.