Before we jump into how to deal with them, let’s do a little refresher on Infested and Teeming. Infested is the new seasonal affix Blizzard introduced in BFA that appears on all keys +10 and above. Any time you have Infested on your key, various mobs throughout the dungeon will have an Infested debuff on them that heals other nearby mobs for 10% of their max health every three seconds. Once the Infested mob is killed, two Spawns of G’huun will pop out and run to nearby enemies and attempt to re-infest those enemies. The spawns must be crowd controlled and killed quickly to avoid a chain reaction of infests. Teeming is a +4 affix that adds extra mobs to each dungeon and consequently requires you to kill more mobs than usual to complete your mob count.
There are two concerns with Infested: first you need to figure out what you want to do with an Infested mob during the pull because it will heal other nearby mobs, and second you need a game plan for how to deal with the Spawns of G’huun once the Infested mob dies. There are generally two ways that you can pull a pack with an Infested. You can either pull everything together and focus fire the Infested mob to kill it, then quickly kill the Spawns before finishing off the rest of the pack, or you can CC the Infested mob before you pull and kill the rest of the pack before coming back to finish off the Infested mob by itself. It will usually be a little bit faster to pull everything together and kill the Infested mob first, but it’s also a lot riskier because it’s easy for your group to lose track of the Spawns in the middle of a big pull. On that note, a friend of mine (shout out Shiftmage) repurposed one of the popular Explosive weakauras for Infested that will show how many Spawns of G’huun are alive and will add a frame glow to their nameplate. You can find it here
https://wago.io/HyoI49iV7. This makes keeping track of Spawns much easier.
If you don’t have much CC in your group, I would probably recommend single target CCing the Infested mobs and pulling the rest of the pack first. Every group should have at least one form of single target CC that you can use on an Infested mob, and it will require a lot less coordination and group awareness to save the Infested mob for the end rather than trying to burn it down first and then scramble to kill Spawns while dealing with the rest of the pack. While it’s nearly guaranteed that you can single target CC an Infested mob before the pull, it’s somewhat less likely that you group will have strong CC for dealing with the Spawns when they pop out. And if you can’t kill Spawns quickly a pull can get out of control fast.
Teeming is a slightly different beast. Unlike Infested, which requires coordination but isn’t necessarily lethal, Teeming can often make packs brutal. This was toned down somewhat last week by a hotfix after Blizzard realized that Teeming had become a woodchipper, so Teeming should be a bit more manageable going forward, but it’s still going to hurt. It’s hard to give advice for Teeming because it affects each dungeon a bit differently, but I’ll try to give some tips for dangerous pulls in general.
As the old saying goes, “Discretion is the better part of valor,” and your first consideration on Teeming week should be whether it’s worth it to pull some of the Teeming packs at all. You should spend a little bit of time at the beginning of every week considering how the weekly affixes affect your routes, but especially on Teeming week it makes sense to really analyze how you want to move through each dungeon. Some Teeming packs just aren’t worth the headache no matter how much mob count they give, and it will make your life a lot easier to just skip them. If you absolutely have to pull a pack that scares the crap out of you, think about saving your Bloodlust for trash. I think there’s a common misconception by groups that lust is a thing that should always be used on bosses, but that’s not case. Lust is often thought of as a time-saver in that it lets you finish a pack or boss more quickly, so people will tend to think of how they can use lust to get the most bang for their buck in terms of DPS. But lust can also be used as a safety net of sorts by allowing you to burn down a dangerous trash pack before it overwhelms you. So consider using your lust for some of the especially gross Teeming packs that you may struggle with. Similarly, try to wait for your group’s individual cooldowns to be up for big pulls. Most classes are going to have two or three minute CDs that will make their damage really pop, so if everyone has their big CDs ready on a pull it can make a dramatic difference in how fast you can melt everything.
Realistically it’s nearly impossible to have a group composition that’s so awful at CC that Infested/Teeming pulls are just undoable, but if it’s really that bad you may have to bite the bullet and consider switching up your group for a dungeon.