Careers teaser in error console.

             _.-~-.
           7''  Q..\
        _7         (_
      _7  _/    _q.  /
    _7 . ___  /VVvv-'_                                            .
   7/ / /~- \_\\      '-._     .-'                      /       //
  ./ ( /-~-/||'=.__  '::. '-~'' {             ___   /  //     ./{
 V   V-~-~| ||   __''_   ':::.   ''~-~.___.-'' _/  // / {_   /  {  /
  VV/-~-~-|/ \ .'__'. '.    '::                     _ _ _        ''.
  / /~~~~||VVV/ /  \ )  \        _ __ ___   ___ ___(_) | | __ _   .::'
 / (~-~-~\\.-' /    \'   \::::. | '_ ` _ \ / _ \_  / | | |/ _` | :::'
/..\    /..\__/      '     '::: | | | | | | (_) / /| | | | (_| | ::'
vVVv    vVVv                 ': |_| |_| |_|\___/___|_|_|_|\__,_| ''

Hi there, nice to meet you!

Interested in having a direct impact on hundreds of millions of users? Join
Mozilla, and become part of a global community that’s helping to build a
brighter future for the Web.

Visit https://careers.mozilla.org to learn about our current job openings.
Visit https://www.mozilla.org/contribute for more ways to get involved and
help support Mozilla. 

• https://mozorg.cdn.mozilla.net/ja/tabzilla/tabzilla.js

// Careers teaser in error console.
$(window).load(function () {
	try {
		// Try to only show on stage and production environments.
		if (/mozill|webmaker|allizom|firefox/.exec(location.hostname)) {
			console.log("             _.-~-.\n           7''  Q..\\\n        _7         (_\n      _7  _/    _q.  /\n    _7 . ___  /VVvv-'_                                            .\n   7/ / /~- \\_\\\\      '-._     .-'                      /       //\n  ./ ( /-~-/||'=.__  '::. '-~'' {             ___   /  //     ./{\n V   V-~-~| ||   __''_   ':::.   ''~-~.___.-'' _/  // / {_   /  {  /\n  VV/-~-~-|/ \\ .'__'. '.    '::                     _ _ _        ''.\n  / /~~~~||VVV/ /  \\ )  \\        _ __ ___   ___ ___(_) | | __ _   .::'\n / (~-~-~\\\\.-' /    \\'   \\::::. | '_ ` _ \\ / _ \\_  / | | |/ _` | :::'\n/..\\    /..\\__/      '     '::: | | | | | | (_) / /| | | | (_| | ::'\nvVVv    vVVv                 ': |_| |_| |_|\\___/___|_|_|_|\\__,_| ''\n\nHi there, nice to meet you!\n\nInterested in having a direct impact on hundreds of millions of users? Join\nMozilla, and become part of a global community that\u2019s helping to build a\nbrighter future for the Web.\n\nVisit https://careers.mozilla.org to learn about our current job openings.\nVisit https://www.mozilla.org/contribute for more ways to get involved and\nhelp support Mozilla.");
		}
	} catch (e) {}
});

https://developer.mozilla.org/ で console を開くと出る。