Thank you for your replies

I agree that he looks a bit odd, he has beautiful feathers but he looks all stained

Thats why i named him Stains! I also think that those white dots above his beak make him look angry from the front
Its true that he has lived with zebras before, so maybe the sound he makes is inspired by the zebras!
I will try to get close-ups - it will be a lot easier to do this when i move them from the quarantine cage to the other birds