Is when your best friend does something silly or stupid to an inanimate object or when a friend does something to you that has offended you. Can also be used as an insult.
Man1 "That ball is so stupid it does not do what I say."
Man2 "Wow you are such a muckelspäck."
Man1 "Stfu you are such a pussy
Man2 "Better watch your mouth or im gonna muckelspäcka you"