In story, these mutant bears were named by the descendants of Chinese interment prisoners from World War III.
As "yāo guài" is apparently a real world term for a spirit or monster creature. Which makes sense, since it's written "妖怪", which just happens to also be the Japanese kanji for "yokai".
But there's a lot of mutant animals in fallout. Why give that specific name to the bears?
Because in the wasteland, you're the pic-a-nic basket.
JFC there will never be a time when the deathclaws don't majorly fuck with my head. It’s like, here I am minding my own business meandering across the deserted wasteland and then suddenly BOOM! IT’S SATAN AND HE HAS COME FOR MY SOUL!!! WHY GOD, WHY?!? HAVE I NOT DONE GOOD?!?