Cowsay is so 90s, time for something new like Octocatsay:

$ wget -q 'https://api.github.com/octocat?s=Time for Octocat!' \
       -O -

               MMM.           .MMM
               MMMMMMMMMMMMMMMMMMM
               MMMMMMMMMMMMMMMMMMM      ___________________
              MMMMMMMMMMMMMMMMMMMMM    |                   |
             MMMMMMMMMMMMMMMMMMMMMMM   | Time for Octocat! |
            MMMMMMMMMMMMMMMMMMMMMMMM   |_   _______________|
            MMMM::- -:::::::- -::MMMM    |/
             MM~:~   ~:::::~   ~:~MM
        .. MMMMM::. .:::+:::. .::MMMMM ..
              .MM::::: ._. :::::MM.
                 MMMM;:::::;MMMM
          -MM        MMMMMMM
          ^  M+     MMMMMMMMM
              MMMMMMM MM MM MM
                   MM MM MM MM
                   MM MM MM MM
                .~~MM~MM~MM~MM~~.
             ~~~~MM:~MM~~~MM~:MM~~~~
            ~~~~~~==~==~~~==~==~~~~~~
             ~~~~~~==~==~==~==~~~~~~
                 :~==~==~==~==~~

You can already make Octocat say something on GitHub, just using this GitHub API endpoint to get an ASCII in plain text in response:

https://api.github.com/octocat?s={message}

Octocatsay was born in 2012, I seem to remember that, but only recently saw it on GitHub Explorer. It’s written in Bash by Coby Chapple, licensed under the MIT License.