Yeats quote

I was in an office with Keith for about 5 years, I guess, and I think the whole time he had this poster on his wall with what looked like a photo of an AT-AT taken with a gameboy camera, accompanied by a quote:

And what rough beast, its hour come round at last,
Slouches towards Bethlehem to be born?

7 years later I finally got around to looking it up, and it turns out it comes from a Yeats poem. Good quote, good poem.