AWS RDS - Create mysql user with superuser Privileges

Login as super user on command prompt.

Run following query to create user.

CREATE USER 'username'@'%' IDENTIFIED BY 'password';

Just change username and password in above query and execute as root user. A new user will be created.

Now give super user privileges to new user.

GRANT SELECT, INSERT, UPDATE, DELETE, CREATE, DROP, RELOAD, PROCESS, REFERENCES, INDEX, ALTER, SHOW DATABASES, CREATE TEMPORARY TABLES, LOCK TABLES, EXECUTE, REPLICATION SLAVE, REPLICATION CLIENT, CREATE VIEW, SHOW VIEW, CREATE ROUTINE, ALTER ROUTINE, CREATE USER, EVENT, TRIGGER ON *.* TO 'username'@'%' WITH GRANT OPTION;

Just change username in above query. Your new created user will be a super user now.