Ok, I've made a new gif animated avatar. I've learnt that on #Mastodon there should be a preference to activate the gif animation, but I've not looked into it.

On my computer web browser I can hover my mouse over a profile and if it got a #gifanimation / #gifavatar then it will animate. On #Android I'll have to investigate if its possible by outside visitors to see if a user's avatar can be animated.