I’m putting an old text into HTML. Sometimes it uses Greek terms and phrases. But there’s one character I’ve never seen before. It seems to be a combination of two other characters: small omicron (ο, ο) + small upsilon with perispomeni (ῦ, ῦ). Here is a PNG illustrating the character, and how it works:

Does anyone know how to put this character into HTML? Can it be found anywhere in Unicode? Has anyone even heard of it?
Thanks.
That’s called a ligature. I couldn’t find any Unicode character for that one, though there is the Latin version of it:
http://en.wikipedia.org/wiki/Ou_(ligature)
Which mentions the Greek.