So happy to have found this rewrite after ToggleGifs (or whatever the name was *bad memory*) wouldn't work with new FF. I'm rating 4 stars only because there doesn't appear to be a way to turn animations back on after you Shift+Esc to turn them off other than reloading the entire page. If that feature could be added (maybe Ctrl+Shift+Esc to reverse), this would be full-on 5 stars for me. Thank you!

Nice! I wish I can set stopping animation as a default preference.
I also wish there is a way to resume playing.

Still works. Hoorah!

Finally I can use amazon without ads being animated and shoved in my face. To me such ads (and tooltips) are the visual equivalent of nails scraping on a blackboard.