This cheat will change the race of your Fallout character, relative to the specified race. Use 'human' to return to normal form. NOTE: You may experience issues switching races if your character does not have default appearance settings. Use the 'showlooksmenu' command to change your character's looks.
player.setrace [race id]
|Race ID||The ID of the race you wish to change to. Use 'human' to return to your normal form.|
If you have previously changed your race and wish to revert back to the default race, the above command will do so.
The above command would make your character's race that of a ghoul (you will look like a ghoul).