You will need to install a user script manager extension to install this script.
See attached screenshots.
The script is fully customizable, just open the "scripts" window and go to the "NERD Portrait" tab, here you can type any text that you wish to see on the portrait, but be careful - text should be a valid HTML, and due to this feature, you can also stylize font color, font size, text alignment, etc, by using all the power of CSS.
After you finished editing, click on the "Save" button. PROFIT!