Most likely the reason why you have come here is that you are confused about narwhals and bacon. And the time at which the narwhal bacons. So, here is a simple explanation.
“The Narwhal Bacons at Midnight” is a catchphrase created by redditors for redditors (reddit.com - check it out and you`ll know what it is). It is kind of a secret "password" that redditors use for identifying themselves in public places, so that the others do not understand what are they talking about. The question "When does the narwhal bacon?" and the answer "The narwhal bacons at midnight" are often seen in funny posters, demotivators and meme comics. So, if you have seen some of those, most likely they were made by a redditor.
The origin of the narwhal bacon.
In 2009 a redditor was kind of bored sitting in an airport. So, he posted a question in reddit.com, if there are any other redditors in the airport, because there were many people using their laptops. And the top voted reply to his question was that "The narwhal bacons at midnight" is now the official phrase to identify yourself as a redditor in a public place.
Since then the phrase "the narwhal bacons at midnight" has become popular everywhere. Redditors have t-shirts, bumper stickers, posters and many more funny things with pictures of baconing narwhals at midnight etc. (you can find them in this blog)