Xandria Ecrithia Kliper (alias Alexandria "Alex" Edith Clipper) is an alien living amongst the Sims in Sunset Valley. She was stranded on Earth alongside fellow alien and friend Zrala Maitolia. They had brought disguises along with them in the event of their landing on the planet and so posed as Sims throughout their stay on Earth. Xandria adopted the alias of Alexandria Clipper, adding "Alex" to her name to "make it sound more Simlish." She also modified her last name to suit the same purpose. Zrala chose to call herself Sara Clipper, acting as Xandria's fraternal twin sister.
Xandria has exceptional memory, allowing her to memorise entire conversations and other such exchanges with amazing detail, resulting in the possibility for her to write full conversations in her diary entries.
Xandria is the narrator and one of the two main characters of Diary of a Young Alien.
- Alexandria - A city in Egypt, capital of Hellenic, Roman and Byzantine Egypt for almost a millennium.
- Edith - Derived from the Old English words Ead, meaning 'riches or blessed', and gyð, meaning 'war', and is in common usage in this form in English, German, many Scandinavian languages and Dutch.
- Kliper - The name of a proposed Russian manned reusable spaceplane created by RSC Energia, the Russian space agency.
- Clipper - The English equivalent to Kliper. Also was the general name given to planes operated by Pan Am, itself derived from the name of a very fast sailing ship of the middle third of the 19th century.