How did Eris get there?

Its name come from a goddess in the ancient Greek and Roman mythology.

Eris is the name of the Greek goddess, who is the goddess of hatred, jealousy, and battle. She is the daughter of Aphrodite the love and beauty goddess and Ares the war god. She is also the largest...

We do not yet know.

Eris is the Greek Goddess of Spite (in Gr. Έρις ). She is the elder daughter of dark Night, Nyx (in Gr. Νύχτα). Her brother is Ares, God of War. She is one of the most hated Goddesses by the...

Eris is another dwarf planet that is sometimes called Pluto's twin. All though, it is slightly bigger than pluto. It was named after Eris, the Greek goddess of Discord.