I've created an administrator-level account called "Administrator" on my iMac (macOS Sierra). I basically did this to ease copying existing user documents, etc. from a backup using the Migration Assistant without any name/user conflicts.
Now I've copied stuff over, I'd like to delete this account named "Administrator". Using another administrator-level account, I login, but when I access the Users & Groups System Preferences, the user "Administrator" doesn't appear in the list of current or other users. Therefore, I can't delete it. Any ideas as to why this user doesn't show up in the list?