A combination of “twat” and “wanker” accidentally/intentionally being combined in a sentence, used to describe someone who is both douchey and an idiot at the same time
I can’t believe they madeLoki do that; they made him look like such a twanker!
A person who is completely clueless, acts like a total jerk, and is entirely oblivious to the fact that they are annoying everyone around them. An accidental dummy.
"Dude, look at that guy who left his shopping cart right in the middle of the parking space. What an absolute twanker."