There is a bug, particularly in cave areas and dungeons where using the wolves’s active ability on druid will have them jump into the sky to land on the target and attack them.
However, they seem to have no problem just standing in the air and just staying at their new found height. Repeated abilities can sometimes have them gain new heights as well, so much so that they can no longer be seen on the screen.
They consistently have problems with higher levels of terrain even when the active is not being used, but this bug is a little bit too much. I think I’ll stick with my reliable poison creeper.