Can anyone explain the grammar behind the "sentence ending" とでも?

Is it an abbreviation of a longer phrase? Or is it just kind of like the American street slang, "And what..?" As in, "You think you're hot? And what..?"

But in this case perhaps it is almost like asking if the listener had any "buts" or objections to the statement.

そんな[怒]{いか}りに[妾]{わらわ}が[怯]{ひる}むとでも？

And you think that anger would make me flinch?

「それが[実証]{じっしょう}できるとでも？」
`You're going to verify THAT?'

あなたに言われないと分からないとでも？
Like I need you to tell me that.

「ほかになりようがあるとでも？」と[女王]{じょおう}さま。
'What would you have it?' said the Queen. (from Alice in Wonderland)

同性愛者ですが何か？それが[犯罪]{はんざい}だとでも？
So what if I am gay? Is it a crime?

Source:

http://eow.alc.co.jp/search?q=とでも？