Another very useful cPanel feature is the Wildcard Subdomain. This allows you to direct non-existing subdomains to a specific folder within your server.
They act as a blanket location, so that if a user is trying to access a non-existing subdomain they will be redirected to a page you wanted them to end up rather than seeing an error on page.
To create a wildcard subdomain:
First, you need to login to your cPanel account.
Locate and click on “Subdomains” under the Domains section.
You will then be redirected to the Subdomain screen that will show you the options to Create a Subdomain and Modify a Subdomain.
Create the Subdomain and just enter an asterisk on the Subdomain field, use the parent domain and your preferred folder name that will act as the Document Root.
This folder stores the page content which the users will be redirected.
Once the wildcard subdomain has been created, you may proceed to the Zone Editor under Domains section and click on + A Record.
A small window pops up and will ask you for the name where you will enter the wildcard subdomain you created.
Please make sure that the Address Field contains your server’s IP address and click on Add an A Record.
Once done creating the A Record, your new wildcard subdomain will be published and users will be redirected to the content that is on the folder you configured.