Continuity mistake: The blood that drips on the girls disappears between shots. (01:06:00 - 01:07:00)
Continuity mistake: The cursed necklace is shown emitting its evil fumes on the white paper of the letter, but the letter itself is perfectly 90° with the envelope, or at a different angle. (00:06:20)
Revealing mistake: Right after the little girl sprays the monster with bug spray, you can see the costume of the monster, it's wearing a black cap. (01:19:00)
Continuity mistake: The chef at the airport stabs someone, but the knife blade is clean afterwards; moments later he stabs it through the valise, and it is covered in blood.
Continuity mistake: At the beginning of the movie, the hunter is looking for his dog. The rifle on his shoulder keeps changing position, being upside down or not - which is easy to spot because of the big scope. (00:01:30)
Continuity mistake: Throughout the movie, fire axes seem to be the weapons of choice. Only two fire axes are used, but they appear recurrently. In the very first use, the protagonists grab fire axes to butcher the monster called Beverly. Blood and gore go everywhere; yet, the axes emerge from this bloodbath with no blood or gore on the handles - they're virtually pristine moments later. The axes are used again and again, right up to the ending, and blood comes and goes from the axe handles seemingly at random.