Google's John Mueller said you can do whatever you want on your 404, page not found pages. He said that includes placing a noindex on it or even better, dancing cats, sneezing pandas, poems, role-playing games and so on. Why did he say that? Simply because Google ignores your 404 pages.
Well, Google will only check to see if the 404 response code was removed, if not, go for the sneezing Panda.
If your site is impacted by Panda, then I recommend the dancing cat.
Otherwise, feel free to get creative. Your 404 pages mean nothing to Google - it is like they do not exist. So have fun.
@piyush200885 You can put whatever you want on a 404: dancing cats, noindex, sneezing pandas, poems, role-playing games, etc; we ignore it.
— John Mueller (@JohnMu) December 21, 2015Forum discussion at Twitter.
