BO7 Zombies Guide

BO7 Zombies Guide - Final Goal: Boss Fight, Defeat Caltheris

 Hold on tight, it's the epic boss fight against a powerful entity known by players as Caltheris, a frosty monster that controls the Christmas event. He could be the embodiment (or an overgrown zombie) of winter's rage. It's not your typical Zombies fight. The standard weapons do not work on the boss initially. The gimmick here is to use Holiday Presents to arm yourself and hurt Caltheris.
 
 The boss fight is a completely new phase. Caltheris takes no damage from your guns - they just tickle. It is better to kill zombies in waves to generate presents. Pick up these presents to gain temporary powerful weapons. Use them to harm the boss. This is similar to a 'gun-game': kill zombies and receive a Gift, the random gift contains a Pack-apunched weapon. Use it against the boss, until you run out of ammo, then repeat. Caltheris is constantly attacking you, making it difficult to perform this task.
 
 Phase strategy - If Cryofreeze is not already equipped, equip it immediately. Then continue the tactic with Gary. The only way to get presents is by killing with Cryo (or snowballs). Focus first on crowd management. Regular zombies will appear in endless numbers (and maybe even elite ones). You can train your zombies in the arena but you should not forget about the boss. He will probably use ranged attacks and slams. To avoid being surrounded or hit by boss attacks, keep moving. Cryofreeze is a great way to eliminate zombies. Look out for a glow on the ground that indicates a present has fallen. They are very rare and the rate at which they drop is extremely low. When you see a gift, run to it and grab it as soon it is safe. This will switch your current gun for a randomly selected Pack-a Punch random weapon (sometimes with a Power-up). Now you can unleash all your firepower onto Caltheris. Now that you've got the power to hurt Caltheris, it's time to get started. Deal as much damage to the boss as you can. If your gifted weapon is empty, or if the boss becomes immune then go back and farm the next present.
 
 Co-op: This is a brutal fight alone. It's almost impossible to win it by yourself due to its low drop rates. With a team you have a greater chance. A division of roles is recommended.
 
 One/two participants focus on the zombie killing for presents, running a train and using Cryofreeze. The "Gift Farmers" are here.
 One player can focus on bosses aggro. Keep Caltheris at bay, avoid his attacks, and deal chip damage where possible.
 You can call out when a present is dropped. Grab it, and then attack the boss. If the weapon is strong (say, an LMG, Ray Gun, or launcher), have the player with Ring of Fire pick it up and activate the Ring to get massive DPS. While the boss is being beamed, other players will cover that player.
 Rotate as necessary (if someone lacks equipment or is low).
 Survival tip: Use Aether Shield field upgrade. (You brought it with you, right?) If you are trapped, or want to steal a faraway gift from the crowd without being seen by them, use Aether Shroud. Aether Shrouds can be used by a teammate to divert attention from the boss for a moment. Caltheris uses heavy attacks, so don't stay still for longer than a minute. Use your Kazmir or Monkey Bombs. You'll have precious seconds left to take out the boss, without adding more zombies to the fray, or pick up that present. Kazmirs may kill zombies which do not drop presents. So, use them sparingly.
 
 If you want to deal with the boss, you can use his weak points: head or glowing parts. With your new guns, aim for the weak points. Don't waste any shots, as the supply of present weapons is limited. If you don't like the weapon, it may be necessary to keep it until a new one arrives. Or if you really hate it, you could decide to hold onto your old weapon instead of picking up the new one (risky because you can't harm the boss without it). In general, accept whatever you receive. You should also maintain your armor. If the armor breaks, you can pick it up from zombies and use a power-up for carpenters. In late game, the boss will be able to one-shot / two-shot unarmored players.
 
 This fight may be long. Intel told us that our biggest complaint was the way presents dropped far too often. "I still haven't gotten a present." I've killed so many zombies so far. You definitely should get them" one operative shouted in the middle of a battle. Be prepared to spend several minutes kiting and grinding before each shot at the boss. Ammo will be an issue here - if the Cryofreeze Gun runs out while farming you'll need to either risk a Munitions Fill on the Map or ask your teammate for Max Ammo. Ammo Caches are often found in the Arena. Take advantage during lulls or when Shroud is active.
 
 After enough cycles, the health of your boss will be zero. Celebrate when Caltheris falls - you've conquered BO7's hardest event! You and your team should receive the Infestation Camo after defeating the final boss (if you've followed all the steps). The Christmas Zombies event culminates with this camo, which shows you have completed all challenges. Infestation camo will be available for all weapons if Infestation is the reward. It glows in the eerie-green of the zombie horde.
 
 You can always try again in case you find the boss too challenging. There are very few players who can solo the boss in this state. If you plan to take on the BO7's Listkeeper Challenge alone, be aware that it is a difficult task. It's possible, but requires flawless execution as well as a bit luck. Bring in friends to help you if your struggles are too much for one person.