PHP’s “doggie” easter egg: There’s a series of Easter Eggs in PHP, based on a specific querystring argument and value.
An apparent easter egg in some versions of PHP will display a picture of a dog when any PHP script is loaded with a particular query string.
Apparently the doggie also appears on the page generated by phpinfo() on April 1st every year.
Here it is on our very own site: Show me the dog. There are several more at the above link