Hide a 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 OS X's menu—maybe 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, that hidden user won't show up as a choice. In older versions of OS X, you'll 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