The monsters in literature that stick with us through the decades are not the ones that come purely from imagination. The monsters that we write about, think about, and make movies about most are either the monsters that we create or the monsters we become. We are afraid of the part of ourselves that is most like the monsters we fear.
One example that supports this idea would be Sasqwatch. Sasqwatch is a monster we fear because he it represents the part of ourselves that is big furocious and violent.

This monster was not really created some explorers went to the jungle looking for new species of anilmals and they claimed to have seen a four feet long foot print in the ground this they named big foot and later in there trip the said they saw a very tall beast who was very hairy and violent and gruesome these people were very scared and never saw them again.

people fear big foot because he is known to be a very tall hairy violent beast roaming throughout the jungle most fear him because he is just ufly and people have a fear of being ugly like on the move hunchback of notre dom people think he is scary cause he is ugly it is the same concept.
in other cases people are afraid of him because he is violent and because he is tall when people think of a tall violent beast roaming the woods they think i am never going to the woods and if they ever get caught in the woods they fear for there lives just cause someone told them that they he is violent who knows mabey big foot is a nice friendly giant and he has nowhere to go cause if he goes into the city people will capture him.

we can learn from this to be accepting and not to fear by what we see or to judge a bpook by its cover its just not right we fear him cause we think we fear him and if we thought we did not fear him then we would not fear him.