A "zombie" is an additional character tied to your account that you can control independently of your main character. They can do almost everything a regular character can, though some things don't quite work with them (for example, who doesn't list any zombies that are in the room). They're commonly used to allow someone to be in multiple places at once.
In ws and some other places, they are marked specially and the name of the account that owns the zombie is shown alongside the zombie's name.
Creating a zombie
To create a zombie, use the editzombie command, which will guide you through the process. After this is done, pman needs to be used to register the zombie so that it will work.
Controlling a zombie is the same as controlling a regular character, except you put a special prefix before the command to specify that the command is for the zombie. This prefix is picked out when you create the zombie.
When something happens where the zombie is, it will display as usual but with the zombie's name before the text.