Short answer: No.
She never existed; Medusa is a myth.
No, Medusa does not really exist. She is a fictional character from mythology.
Yes, she did. She was one of the three gorgons.
That is what the myth says, but it is only a myth since Medusa does not exist.
Jellyfish exist as either a medusa (adult free-floating) or polyp (immature attached) form during their life cycle. Another example is the Portuguese Man o' War, which also has a medusa (floating) and polyp (attached) stage.
According to most modern beliefs, no, Pegasus does not exist. In Greek mythology, Pegasus was a winged horse that came out of Medusa when she was beheaded by Perseus.
Most freshwater hydrozoa exist only as the polyp form. They never switch to the medusa form, or sexual form. This means they exist only in the asexual form.
Poseidon was Medusa's boyfriend and they were hanging out in Athena's temple. Then Athena turned Medusa into Medusa.
Organisms that exist in both medusa and polyp forms belong to the phylum Cnidaria, which includes jellyfish, corals, and sea anemones. In this life cycle, the medusa form is typically free-swimming and reproduces sexually, while the polyp form is usually sessile and can reproduce asexually. Examples include the common jellyfish (Aurelia aurita) and various coral species, which exhibit these two forms at different stages of their life cycle.
Medusa had no children.
No, Rhea was not Medusa. Rhea was a Titan. Medusa was a Gorgon.
Medusa.