The symbolism of the mist changes in the final scene of the novel it goes from symbolizing

The mist is a horror novel which was written by Stephen King. In the earlier part of novel, the author has symbolized the horror which surrounded Bridgeton by using the concept of Mist or Fog. But in the final scene of the novel, he converts this mist to some unnatural monster like a crab having or giant lobster. The main characters however finally find their way out of that mist and drive to Hatford, a new town