suck a big dead moose cock
A very graphic Canadian insult indicating that the person to whom the insult is being hurled it thought of so lowly that they should do this most disgusting of things normally as it is clearly something their character indicates they would consider normal practice. In other words, the person is disgusting and so are their habits.
esp. heard in rural Ontario when someone says or does a thing to anger their associates they would be told to 'go suck a big dead moose cock'. Also heard as a reply to another insult... i.e. if X says to Y 'your mother wears army boots', Y might be heard to reply with 'oh yeah eh, well your mother sucks big dead moose cock'. And on it goes like that until one of them gets a bloody nose.