All the other sites seem to be doing this...
We need an image that will be displayed when users try to bring up a page that does not exist.
Please quote the source so the team can negotiate rights if necessary.
You should talk to our new network administrator.
Another idea I had.
The entire webpage is the bottom of a book. This book has a lot of pages. The footer of the book says "Ubuntu StackExchange" (or the name of the site once that's agreed) and the page number 403 on the next "page" the same footer "Ubuntu StackExchange" and the page number 406 and an obvious tear in the binding where page "404/405" would be.
For as you can see, the page "404" couldn't be found!
I think something more simplistic.
Giant text, that says "404" after a few seconds though the number starts increasing slowly then more rapidly until it stops at 9,001 small text under the GIANT 9,001 says simply "This page is over 9,000" then a redirect to the home page should be in order after that.
From Be the Wumpus.