Its the page your users never want to see, so it makes sense that you might not consider designing a clever 404 page. But the the best 404 pages are not only a functional contribution to the user experience, but they can all provide a brief moment of delight in what could be a frustrating moment.
The best 404 pages often do this by providing a moment of humour, entertainment or surprise that can stop the user from automatically hitting the back button or exiting the page, which could mean the end of their journey on the site. And some even take advantage of the moment to reinforce a brand identity through a memorable, perhaps even shareable, user experience that can feel like finding a hidden Easter egg in a website.
