Krindor did not detect true evil, but malign cause in the creature's thoughts. It may be considered evil, but only because it is a viciously predatory creature... so in other words, "vaguely evil."
(Loud Boom = The sound was like a huge steel spike being driven into the ground... like huge as in the size of a wizard's tower, coming from the direction that the large object floated off towards.)
Tell me when your all ready to move on, the creature has managed to run like a chicken (it even has a beek and clawed feet!) and I doubt it will return without making a very good will save against fear...