The Necroa Virus in Plague Inc. is essentially a Zombie plague that acts completely different than any of the other plague types.
Certain Necroa abilities aren’t unlocked until you get to the Necroa symptoms. It also completely removes the Evolution Gene and replaces it with Necroa genes that have to be unlocked by beating the Necroa virus.
DNA Gene - Cytochrome Surge (Get more DNA from popping orange DNA bubbles)
Travel Gene - Aerocyte (Increases the chance of your plague spreading by air)
Necroa Gene - None
Mutation Gene - Creationist (Reduces the chance of mutation)
Environment Gene - Extremophile (Minor bonus in all environments – I like this one instead of the specific environment bonuses, but it’s not vital)
This one took me a few tries to figure out. Here is the basic strategy that I used to beat it the first time.
Start in India, as it has a large population and access to both an Airport and Sea Port. It’s also a hot and humid country which will give you a boost to hot and humid environments, and you’ll only need to purchase cold type abilities.
Don’t purchase any Symtpoms until the end of the game when everyone on the planet is infected. If you have to devolve any mutations early in the game, you might as well start over because you may not have enough points at the end to finish properly since devolving is extremely expensive in this plague type.
Start off with Blood 1 and Saliva 1 in Transmissions. Also purchase Drug Resistance 1 and Cold Resistance 1 on the Abilities page once you build points.
As you get more points, purchase Urogenital Expansion, Gastrointestinal Expansion, Air 1 and Air 2 for Transmissions. Also purchase Cold Resistance 2 for Abilities.
From here it’s a long waiting game. You’ll literally ride out this build until the entire planet is infected with your plague. Hopefully by the time everyone is infected you’ll have 60+ points banked up. If you’re a little short, then keep waiting a little longer to pop some of the orange DNA bubbles, or until you get a free Insomnia mutation.
Once you’re ready, purchase the following symptoms: Insomnia, Fever, Photophobia, Delerium, and Cytopathic Reanimation. Once you purchase Cytopathic Reanimation, you’ll start the Zombie phase.
The rest of your purchases will be making your zombies stronger and better at killing. Anaerobic Reanimation, Enhanced Motor Control, and Enhanced Sensory Integration were the first ones I picked.
Soon the world should create a zombie task force called ZCOM, which will attempt to go out and kill your zombies. This is represented by black zombie bubbles that you can pop, which will your biggest resource for the end of the game.
The cure will start building fast, but you should also be getting points very quickly while popping ZCOM bubbles. Keep throwing more points at more zombie symptoms and abilities, focusing on making your zombies stronger and making them decay slower.
Soon, the cure will essentially stop and the world will throw in the towel. Congrats on your first Necroa win!