What is Ü

What is Ü called/known as? I’ve heard people around me refer to it as “the smiley face” but is it actually okay to call Ü “the smiley face”?

https://en.wikipedia.org/wiki/Umlaut_(linguistics))

ASTEROIDCHILD [#2]

https://en.wikipedia.org/wiki/Umlaut_(linguistics))

Thanks I’ll look at this tomorrow