You may also find that there are specific challenges during the event which will reward you with bonus XP. (Check the tab "Events" for the Holiday Challenges - they often include daily objectives rewarded with XP). Completing Listkeeper's quest could grant a significant amount of bo7 bot lobby XP. It may also give you the Dark Ops Calling Card. Every camo unlock grants XP. This guide will help you passively level up by doing the Easter egg tricks and using the "free-fire" trick. One operative stated that Endurance (also known as "Endgame") mode in BO7 zombies yields a lot of XP.

 Summary: If you are looking for the BO7 Christmas Farm, the akimbo Shotguns + Free Fire glitch plus DoubleXP is your best option. It's like a ticket to maximum level, while you enjoy the winter. It's important to take in the experience itself. Blasting without challenge can be fun but it isn't worth earning camo.

mmoset BO7 Zombies Guide: Known Issues, Final Tips

 Finally, you should be aware that there are some bugs or issues with this event.

 Low Drop Rate (Boss Battle Frustration). The final boss's drop rate is very low. This makes it difficult to fight, especially if you are playing alone. In our experience and that of many players, "every 3 zombies should be dropping a present", instead the sparse drop now. Treyarch will likely adjust this through a patch. A grind is expected in the meantime. If you want to do it on your own, you may have to try many times or develop a strategy that works. Do not feel bad if a friend is needed to assist you. Infestation Camo is supposed to be rare, so the road can be tough.

 Field Upgrade Glitch - Some people have reported that your equipment or upgrades don't always activate when you trigger them (e.g. Power Keg's gobblegum/consumable failed to pop. One operative became angry that his Power Keg had not deployed during the boss fight, which may have been a bug. You can mitigate this by not repeatedly activating - only tap the button once, then give it half a minute. Be sure to have the consumable in your possession. In the event of a failure, always have a backup. (For example, in the case that your invincibility Gobblegum fails you can run or use Aether Shroud).

 Quick Revive/Auto Reviving Issue: In this mode, it appears that the self revival (whether via Quick revive tier or kit) may be bugged. "No, this stupid augment doesn't even work!" "We fixed that about two updates ago, and it's [broken] again" - This suggests that an auto revive that was supposed trigger failed. Never rely on a perk alone to save you in solo. Keep manual Self-Revives handy. In coop, if a teammate doesn't get up, you can revive them manually if they don't get up.

 Elemental Pop & Random Killed: As already mentioned, the Pack-a Punch effect or Elemental Pop can sabotage your precision challenge. It was reported that the Fireworks effect of a PAP'd weapon "made this way harder, because it kept poppin and killing [my entire horde] unexpectedly." If you own a gun that produces an unwanted effect (fireworks, Brain Rot, zombies etc.), swap it out or re-package it to try a different one. If you have a weapon that has an undesirable effect (Fireworks, Brain Rot turning zombies, etc.) then swap it out or repackage it before beginning a challenge which requires controlled killing. You can choose to shoot another weapon instead of the one that gives the desired effect.

 "Oscar," and Other Unseen Items: The transcriptions mention that you won't be dealing with Oscar in the Listkeeper task. Oscar could be either a mini boss or a side mission on the normal map. Listkeeper bypasses certain quest elements. (Power was On, as noted). Do not be surprised if some map events do not occur (such as an intermediate Boss named Oscar) - this is part of the mode. You should also be prepared to handle an unexpected challenge boss with your new weapons if it appears. This could have been an artifact from playing during an event.

 Co-Op Sharing - Make sure all players in co-op get credit for unlocking camouflage. Normaly, if someone completes the goal in a cooperative Easter egg, the reward is given to all the players (for example, Mutilate was unlocked by all the players after the outdoor challenges were completed). You can check in your camo list that you have unlocked each camo. You might each need to complete certain feats if it is not unlocked. Work together and communicate - it is after all the season for giving.

 Extraction (if it's available): If for some reason you want to quit after you get what you need (say, you unlocked Mutilate & Moonstone and you don't like Infestation now), be sure to do so at a time when you feel safe. You may not have the option to exfil during the final challenge or boss. If you give up early, you might lose all your progress. If you are killed, you will have to start over.

 Finally, be proud of your achievements. You've basically completed a Zombies Easter Egg, under extreme conditions, and have also earned some unique Christmas camo along the journey: Mutilate a gruesome prize for your outdoor survival, Moonstone a brilliant camo which shines like moonlit flakes (likely acquired during the early test), or even Singularity if the rumors about it are true. Infestation, a camo that symbolizes your control over the undead.

 Conclusion

 It all began with a spark, the lighting of fires. And ended in the extinguishing of the greatest threat to the winter. It is not just a piece of camo, but a badge. The veteran who played the game said "I was aware that I could die. But, if you did it alone, please let me hear about it." - this is testament to just how difficult this task was. It doesn't matter if you played solo or in squad, but you still won. Use that Infestation shamrock camouflage proudly to tell the world you've beaten the BO7 Zombies event.

 Now it's time to go and kill zombies. Enjoy the carnage, and have a happy holiday!