Oh naz, sooooo cute.

Was wondering where I saw that weasel before. Tag added.

More to the point, weasels should eat rats and mouses all the time.

Nazrin is like:
"Don't talk to the weasel Charlie!"

I think there's a really big possibility that a Kamaitachi will actually appear in Touhou.
She could be Nazrin's nemesis,
Youmu's sparring partner,
or Momiji's junior.
But that's just me.

it will probably appear once in manga then that's it

Watched a video of someone taking their weasel to deal with a rat problem. Things are scary efficient at killing rats