I may have imagined this. But a few years ago on my forum signature I had a code that would randomise what image was selected. Is that a thing? I'd like to do it with my profile so a randomised background will show up from a few choices.

Yes there is this and it is possible to have your profile have a random background image below is the code, just replace the placeholders with the urls of the images you want

body { background-image: url('URL_IMAGE2')}; }

Please let me know if you have any other questions