A shit-flinging-monkey (simular to a douche pelican) refers to a person who is complaining/ mooching/ or just being an ass hole. Shit in this case is a metaphor for the stupid things this person is complaining or bitching about. "Flinging their shit at everyone".
However you can like a shit-fliging-monkey. I have one as a friend he is very nice and cute like a monkey but every once in a while he flings his shit like a rabid monkey.
"So i talked to him today and he was acting like such a shit-fliging-monkey."
"i dont want to hang out with thoes shit-flinging-monkeys...i'm tired of that shit..."