For a screensaver you can just search the term fish and click the picture that you like and look for a higher resolution and size for it then save it to your computer. After, you can just do the normal settings on changing your screensaver.
The CNET Downloads website has screensaver software available for downloading, many of which are free or free to try. Microsoft is another website that offers screensaver software for downloading.
The Retro Screensavers website has the flying toaster screensaver available for free download, along with a number of other old screensavers. Worth it for the nostalgia value!
Organizations such as the National Wildlife Federation or World Wildlife have free wildlife screensavers available for download. Typically, any other sites which offers free screensaver for download will have some related to wildlife.
Nvidia.com is a reputable website with many unique and beautiful screensavers you can download for free. Amazon.com also has some screensaver packages available for purchase and download.
bittorent
There are many websites that allow one to download snow backgrounds to use as a screensaver. One can get them from 'Screensaver Gift', 'CNET' and 'Google Play'.
Yes, you can download the 3D Pipes screensaver from the Internet as a zip file. Open the zip file on your computer, extract the files and save to your desktop. Once the files are extracted and saved install the screensaver and you will be able to run it.
you can download it on the internet depending on your device compatibility & capability.
big fish and mostfungames.com
download
If it's an existing video on YouTube, download the free "Video Saver" from http://www.screensaver.com/download/ScreenSavers/Video-Saver . Enter the URL to the video on YouTube in the settings and click on "Save Settings" - done. If the video is not on YouTube, you could just upload it and set then enter the URL to the video as described above.
find out who distributes / supports that screen saver. go their website and download and install the software. Please support the software by paying what the developers charge for the work done