> Maybe all errors should be presented with a simple, distinctive and memorable theme - e.g. show a pig photo in that one maybe they'll remember "I got the pig error"

This sounds like the thing that they do in parking garages where each level will have a color, an image, or sometimes even a musical theme. (Which is to say, it sounds like a good idea!)

Could make cute pictures and brighten support staffs day. 'I got a pig telling a chicken that the barn is closed??'

That’s a good idea - and even technical users would find that more memorable than 1198854 versus a 1197854 error.

I think you're going to find people mistaking one animal for another.