Instructions
Start the PCGen software by clicking on its icon. A window labeled "Load Sources" appears. Select the game system sources you would like to use by double-clicking on them. The main PCGen window will finally appear.
Select "File/New NPC" to create a new character. A pop-up window will appear and offer several choices. You can change many of these choices to fit your vision of the character. For example, you may want to change alignment from "Lawful Good" (the default value) to something like "Chaotic Evil" (more fitting for the undead).
Select the "Race" drop-down box to select the undead race your creature can become. Examples of undead races include skeleton, zombie, wraith, ghost and specter. There are many more to choose from. Select one that best fits your vision for the character.
Fill out the rest of the form as you wish. For example, if you want your undead character to be a skilled fighter, you can click on the box labeled "Class#0" and select "Fighter." If you want him to be a weak "Fighter," leave the level alone. Otherwise, increase the level (it goes up to 20). The level box is located right next to the "Class#0" box.
Press the "OK" button. The software will create the creature for you and generate a random name, statistics and more. The creature is now ready to print out onto a character sheet or used as is.