Ruby is amazing! Here’s one easter egg:
ruby -r irb -e 'IRB.send(:easter_egg)'
Or start a ruby shell, type RubyVM and press Tab twice.
It also works in Docker, sort of, you need to provide the :dancing argument.
docker run --rm -it ruby:2.7.1-alpine ruby -r irb -e 'IRB.send(:easter_egg, :dancing)'