Trivia: What is this symbol that AWS EC2 displays once you SSH into the machine?

You can make your custom ones using utility figlet. 'showfigfonts' will show you what fonts are available, the one aws uses is named "standard"

We make custom banners like aws by ebextensions. ie create file .ebextension/000update-motd.config

commands:
  setup_banner:
    command: |
      yum erase -y update-motd
      unlink /etc/motd 
      amazon-linux-extras install epel -y
      yum-config-manager --enable epel
      yum install -y figlet
      # Add Motd as Beanstalk Environment Name
      echo `{"Ref": "AWSEBEnvironmentName" }` | figlet -f standard > /etc/motd
      # Add warning disclaimer from your code ( optional )
      # cat /var/app/current/.platform/banner  >> /etc/motd  

    test: rpm --quiet -q update-motd  || [[ ! -f /etc/motd ]]
    ignoreErrors: true

It's ASCII art that says EC2. That stands for Elastic Compute Cloud