The first ever Mozilla build I've downloaded is Mozilla 0.8. At that time, I have only half years of computing experience. I was quite excited to discover an easter egg when typing about:mozilla into the Location or Address bar. If you try that on Internet Explorer, it shows a blue page. But on Mozilla, it shows a nice verse, in white text on red background. The colours almost spoilt my eyes the first time I see it. Now, I've get used with it and thinks that it's pretty cool.
From the MozillaZine forums, I found out that about:firefox works too! This easter egg shows a different verse and is only available if FireSomething extension is installed. So, there's no big deal that about:firesomething works too. There are many more prophecies compiled by kennethf, which I think, accumulated throughout the development phases of Mozilla. All of them sound so literary. Are those verses meant to be jokes? I don't get it though.