Hide Specific User Account in OS X With This Terminal Command
OS X: It’s rare, but if you ever want to hide a user account from the OS X menu – perhaps for added security or to avoid confusing novice users – this terminal command will do the trick.
In Yosemite, open a terminal and run the following command, replacing hiddenuser with the account you want to hide:
sudo dscl. create / Users / hiddenuser IsHidden 1
When you reboot, this hidden user is not shown as a selection. On older versions of OS X, you need a few extra steps, which you can find at the link below.
How to hide a user account in OS X | Apple via OS X Daily