Just had a chance to watch this, and it was frightening to say the least. Mulder and Scully were brought in to help the Baltimore P.D. solve an a murder and they end up finding out that there's more to the case than meets the eye.
The acting in this episode was pretty good for the most part, with Doug Hutchinson doing a great jobs as Eugene Tooms. He's one of the more frightening monsters from the first season. Hiding out in the darkness... sometimes it pays to have a baddie do that... instead of being right out in the open.
The atmosphere in this episode was just chilling and dark, and it worked with feeling of the episode as well. You truly felt as if the said monster was going to go after you too.
As for moose and squirrel themselves, they ended up doing a FAR better job in terms of finding out the truth than the cops themselves did. All the cops did was be inept, and make fun of Mulder. On a side note, wanted to knock them upside the head for that XD. Scully's friend Tom Colton (who's an FBI agent himself), did the same in terms of not taking Mulder seriously. Pretty much they all treated him like he was some kind of nut case.
Overall though, this is one episode that is worth the watch and the special effects hold up pretty well after all these years.