Birds wears a green Kokuyo uniform, and top hat. He is an old man, but broke out of prison to aid Mukuro in finding Tsuna. He has multiple yellow birds which follow him around and double as a signal to Mukuro if he is defeated. Birds also seem to find pleasure in other peoples pain, as he has a nosebleed when ordering Tsuna's friends to beat him. Source: http://reborn.wikia.com/wiki/Birds