Deleting the MySQL 'root' user on purpose
You can rename the 'root' user.

To rename the administrator’s username, use the rename command in the MySQL console:

mysql&gt; RENAME USER root TO new_user;


The MySQL “RENAME USER” command first appeared in MySQL version 5.0.2. If you use an older version of MySQL, you can use other commands to rename a user:

mysql&gt; use mysql;

mysql&gt; update user set user=”new_user” where user=”root”;

mysql&gt; flush privileges;


From here.