Ever since SGR got Brainrotted, I haven't had to worry about combat revives. (Although I do worry about all those used sharps laying all over the place. I've been hit five times in one night! Seriously!) My other zombie gets hit occasionally though. How do I deal with it?
1. Cure that Infection! If you spent any time as a zombie you're probably Infected upon your return. Get thee to thine hospital as quickly as possible. (Or don't. You'll just be a zombie again.) A fun twist that often works (especially when you're almost out of HP) is to just crash into a safehouse and yell, "PLEASE HELP I'M INFECTED!" and log out. No one wants an Infected survivor dying in their safehouse. You'll probably get the heal.
2. Got armor? If not, go to your nearest PD and get a Flak Jacket. Survivors will have to expend approximately 20% more ammunition to kill you; factoring in the AP required to find the ammo, then the AP to kill you, you're imposing a heavy penalty on them without griefing any baby zombies who decide to munch on you for quick XP. This is important: get the Flak Jacket. Hell, get two, just in case you screw up and drop the first one accidently. (Like I did.)
3. Spend those XPs! Bodybuilding imposes another 20% penalty to the survivors trying to kill you. Knocking down a Superzed (with Flak Jacket and Body Building) really takes some AP, thereby taking the heat off the rest of the horde. NT Employment allows you to spot the NT buildings easily. Diagnosis renders most of the zombie Scent Fear skill tree redundant for only 100 XP. Various combat skills and Free Running are optional -- more on this later.
4. (Optional) Get an Axe, Crowbar, some guns and ammo, and a GPS unit if you find it necessary. Might as well grab a few syringes as well so that your zombie buddies who are lacking armor can get some.
What next? You have some options.
1. Return to death. Jump out a window if you're in a hurry; otherwise, park yourself back in the horde and let them handle it. The younger zeds will appreciate the easy XPs and getting back up will cost all of 1 AP if you have Ankle Grab. If you're feeling particularly devious, allow the Infection that you probably have upon revival to kill you inside a safehouse. Good times.
2. Zombie spy. Scout out all those buildings that you couldn't tear the barricades off of, take notes, and tell the horde. This is frowned upon in some circles but if Kevan didn't want you doing it, you wouldn't be able to. Feel free to bust down barricades with your Crowbar if you're so inclined. If you're feeling particularly mean, overbarricade the resource buildings while you're at it.
3. Death cultist! Remember that Axe and those guns? Track down the punk that combat revived you and do some combat devival instead. Go after his friends if you'd like as well. The best part of it is, some survivor will have to use yet more AP's to kill you for it, making you a zombie again. Great, huh?
4. All-out griefing. Change tags creatively. (Turning "Entry point: Keep at VSB" to "Keep at EHB" is a favorite, as is changing "Revive Point" to "Revive Point CLOSED, Revives now at [false location].") Smash generators in malls, warehouses, NT buildings and hospitals. (This is particularly bad with the new search protocol.) Tear down barricades on buildings under siege. Overbarricade entry points. Go into heavily crowded areas, such as malls, and accuse random people of being PK'ers, GK'ers, or zombie spies. (Spraypaint it around as well. People listen better to tags for some reason.)
Brief stints of life for a zombie are a blessing in disguise if you're ready to take advantage of them.
The war of humans vs. zombies will be won by AP's and AP's alone. Whatever you do as a zombie, always consider how best your AP's may be spent. Shredding that injured Level 1 newbie that got caught outside the barricades is fun and easy XP's, but did you need the XP's? Upon entering a mall or safehouse, don't go for the quick kill if you don't need the XP's; instead, kill the important people. (NT's, barricaders, and headshotters are your best choices. Or better yet, bite everyone in the room once, smash their genny, and move on to the next room. It usually takes more AP's to find a First Aid Kit than it does to bite someone and Infect them and some of them won't have FAK's at all, meaning that they'll lose HP while searching for one and it'll cost them even more AP's.) If there's an active defender, bite them once and move on; they'll probably run. If they stay, let them attack and keep refreshing, and be ready to hit that Stand Up button. They'll have essentially traded most or all of their AP and ammunition for 6 AP of yours. This is one of the most effective tactics that a zombie can use. Theoretically, a Superzed could wear out seven or eight defenders before AP'ing out; done several times, a mall would be essentially defenseless for 24 hours. Think about that.
Edited to add: if you're not already a maxed out zombie, disregard the above. Focus on maxing out. If you find yourself human, DO get the armor, DO get Bodybuilding, and DO get Diagnosis. The rest should wait until you're maxed out. Brain Rot should be the absolute LAST skill you ever get, as it'll be very hard to be a human again. Put it off until you have all the human skills and equipment that you want.