It is a term that British people use. People outside of the UK think it sounds ridiculous, so the modern stereotype or newfag would think that British people have very poor grammar. It basically means, "You What Mate". Those 3 words don't even make a proper sentence, therefore it is a funny thing to say and a way to make fun of Brits'
Benjamin: U WOT M8
''U Wot M8'' or ''You Wot Mate'' is usually used when a person doesnt hear what the other person is saying, it also can be used in arguments or before a fight which is spoke in a quick aggressive manner, the term ''You Wot Mate'' has been around since the early 90's and the term has recently confused Americans as expected.
Your mums a slag....
U Wot M8? you wanna a fucking slap?
No, i was just joking mate, sorry.
''text'' speak for ''you what, mate?''; which is stereotypically used around the UK (specifically Newcastle and Liverpool). This phrase is usually used within Dolan
comics, for its grammatical inaccuracy and confrontational tone
Dolan: U WOT M8?
U Wot M8 is just text slang for ' You what mate?' - a confrontational phrase used mainly in Northern England. Normally in response to another confrontational phrase - see example below. It does make sense though is abbreviated, it is a shortened of "YOU are going to do WHAT, MATE?" Mate being the obvious indicator that there is trouble afoot. This abbreviation is probably the cause of much confusion to the American audience since they have similar difficulty with 'half two' meaning half past two (not one or one thirty like some of the common guesses).
"I am going to twat you."
"U Wot M8?"
"I did your Mum last night!"
"You what mate?"