So I've noticed the following lines in the message log:
The mist wolf attacks the ghost bat. The mist wolf misses the ghost bat. The
ghost bat attacks the mist wolf. The ghost bat misses the mist wolf. The
mist wolf attacks the ghost bat. The mist wolf suddenly can't move! You hear a
ripping sound.
My mist wolf companion has been standing motionless for over 500 turns now, 'l'ook command doesn't show any status. I can't check the tile version as it's from the server.