an 'ugly duckling' that has become a beautiful swan [=an ugly/unsuccessful person or thing that has become beautiful/successful]
('informal') That dog of yours is '(as) ugly as sin'. [=very ugly]
The house is an 'ugly duckling', but it has a lot of potential.
(..) I mean, can we afford a nanny? And if we can, we can't get a pretty one, 'cause it'll wreck our marriage. We can't get an ugly one, 'cause it'll scare the kid. I-I don't know, Howie. Are we in a good school district? You're Catholic, I'm Jewish. (..)2016 TvShow: The Big Bang Theory Title: The Positive Negative Reaction Season: 9 Episode 16