There are numerous annoyances in zombies, which mostly happen only when you play with people found through matchmaking.
-Stealing your kills in first room
-People not opening doors
-Hugging box when it has been found, usually they just refuse to buy any wall gun/Juggernog, just Bcuz i can haz raygun!!!!!!!11!!
-When electricity has turned on and way to Juggernog is open, they still refuse to buy it...
-In Kino, when your ready to go to Pack-A-Punch, its all linked and round has started, I don't want to go there alone because they might want to come with me as well, but no they still aren't coming to teleporter so I'm forced to go alone :roll:
-Not protecting Juggernog in Ascension from Space Monkeys because they are busy on shielding PhD/other less useful perk
-People going down in early few rounds, I consider that to be marker saying "You will have alot work on reviving them this game"
-Not reviving someone whos downed while they are slaying zombies next to him and I'm coming from other side of map
-Ragequitting because of getting downed/dying
-Mates who dash for power ups, for example Max Ammo after dogs/monkeys just because they have weapons already reloaded, screw other 3 players...
For Box huggers I have solved problem. Just throw grenades on box slowly when they open it, they either go down by trying to throw it back -> I wait until weapon is gone and then revive, or they just can not pick that weapon from box. Maybe that teaches them to get first wall weapon and/or Sickle/Jugg before spamming box.
And of course to people calling themselves pros at zombies and yelling at others when they don't do what he wants(most of time its something idiotic), get good lesson when I revive them again and again, they will probably go quiet at this time. This is extremely fun when you have Quick Revive + Jugg and they happened to get bad weapons from box and start to going down... fun begins 8-)
But best advice you can do to them is being good and helpful to them and ignoring their lack of skill and/or stupid words.