Could this be avian pox or likely something else? 
Thanks for the reply! I'm glad if that's the case...I tried to look through the forum but couldn't find much apart from avian pox... So I'm glad if it isn't something that could spread to the other birds!
Alan W said:Hi lgelchen
It looks like a Tick and hopefully will eventually drop off.
I agree with Alan, a tick.
Often a very underrated critter, not just for animals, birds etc, but for humans as well. More info can be found on the Lyme Disease Action website.
https://www.lymediseaseaction.org.uk/
Mike