This is one of the reasons why I love Cantonese: 咩! (Meeh, wot? or what kind of…)
My theory: It started out as 乜嘢 (mat yeh, what thing. As in: 你飲乜嘢呀？Lei yam mat yeh ah? You drink what thing ah – what are you drinking?). A good Cantonese expression that Mandohooligans can’t understand, in speech or writing. And then (again this is my theory but I think a good’n:) it slowly compressed into one word: Meh (咩）taking the beginning from the mat and the end from the yeh.
And then MEH took on its own life, meaning ‘what kind of’ as in 你飲咩啤酒呀? (Lei yam meh beh jau ah? You drink what kind of beer?) But it created a conundrum. How to write it? Normally in Cantonese if a word doesn’t have its own character you just take a word that sounds identical or similar and slap a ‘mouth’ character (口）on it. Like 呀 (ah) that comes from the word 牙 (tooth). But there is no ‘meh’ sound in Cantonese. What did they do? Wrote it as ‘the sound of a goat’! (Or sheep.) 咩(meeeeeeh!) Goat falling off a mountain!
By the way, the above photo was taken on an excellent day in Inner Mongolia, hitch-hiking through the wilderness.
喂！ 你搵乜嘢呀！ (Wei! Lei wan mat yeh ah? Hey! What are you looking for?)