The Origin of Legendary Creatures

Giants may really exist...

The imagination of sacred creatures and gods may be able to be separated into two causes:

1) An imagination of a person: Imagination is mainly within one person, some incredible creatures like the Chimera were impossible to be accepted. This kind of imagination might be started by:
a) A desire to do something: People wanted to fly since they saw birds flying freely, they might have thought that some people may has wings to fly. Most Egyptian gods have wings, like Isis and the Sphinx.
b) Poor discovery: People before 16th century rarely discovered the outer world; they thought it was danger out there. They thought many dangerous creatures (imagined by them) could hurt them.
c) Religous effects: Almost each ancient religion has its own sacred animals, I can’t figure out how they started to think about it. Besides, those sacred animals were often cats, birds, serpents etc.

2) A true witness: Among all legendary tales, some of them maybe true. Some creatures are explainable, like European dragons, hybrids, dwarves, and giants. After the Renaissance, people began their journey of exploration. Besides these, the creatures in ‘The Odyssey’ might be true, but not all. I reckon the following factors maybe the origin of legendary tales:
a) Rumors: A tale of an explorer may pass to another person and spread to the whole country. When the news was spreading, who knows its contents won’t change?
b) Aliens: Ancient people do not know about outer space, they thought humans were the only intelligent creature. When they saw an alien, they might create a bunch of stories and tell the others.
c) Mutation: A variation may happen among the animals living in the forest, when a hunter or a peasant saw them; in that time, no scientific fact could tell them what was happening.
d) Enlarged creatures: An octopus may be normal, but a giant octopus may frighten someone. Some of those legendary creatures may be enlarged animals, especially sea monsters. In the old times, items for exploration were weak; people couldn't decide what was on the seabed when the weather was bad. Besides, they might have seen mirages.

The above passages are my opinions, I wouldn't bet that they are totally right…