Also: Hermoine's nom de guerre.
Since she usually says up nights to study, Night Owl works. =)
Strigiformes is the scientific order name for Owls.
From http://www.owlpages.com/articles.php?section=Other+Owl+Stuff&title=Owl+Words
Strigiformes: All Owls are classified as members of this order. The name is formed from "Strig", the plural form of the Latin word "strix", meaning "owl" and "formes", meaning "forms".
So, from that, Strix means Owl.
Nox is Night in Latin.
Strixnox? Striganox? shrugs
If or When they go through the process for Animagi, I can see Hermoine becoming an Owl. (or not, seeing as she really dislikes heights. Cat maybe?) Harry... Hmmm... Maybe a Phoenix or some form of Dragon would be apropos? Unsure, but with his penchant for Flying, I wouldn't be surprised.