also: なんじゃそら
expression
what's that?; what the ...
Colloquial exclamation expressing surprise, disbelief, or annoyance at something unexpected or absurd. Often used in casual speech, similar to 'What the heck is that?' or 'What on earth?'.
机の上に変なものが置いてある。何じゃそりゃ？
There's something weird on the desk. What the heck is that?
彼が急に辞めるって言い出したんだ。何じゃそりゃって感じだよ。
He suddenly said he's quitting. I was like, what the ...?
A more standard and less colloquial way to say 'What's that?'. 何じゃそりゃ is rougher and more expressive, often used among close friends or in informal situations.
Colloquial contraction of 何だそれは (nan da sore wa), with じゃ (ja) being a casual copula and そりゃ (sorya) a contraction of それは (sore wa). The variant そら (sora) is a further contraction.