Final answer:
The most likely meaning of 'dreadful' in the sentence is inspiring fear.
Step-by-step explanation:
The most likely meaning of dreadful in the sentence is inspiring fear.
The word dreadful implies that the creature is extremely frightening or causing great fear. The description of the creature emerging from the swamp, roaring menacingly, and crawling toward the town supports this interpretation.
It is important to note that dreadful can also mean causing awe or inspire a feeling of great admiration or respect, but in this context, the emphasis is on fear.
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