Police are appealing for witnesses to an assault on a man in Brighouse.
The victim was walking along Huddersfield Road from Brighouse and was approaching its junction with Millroyd Street when he was hit from behind.
He suffered a broken jaw.
The suspect is described as around 6ft tall.
Anyone who saw the attack, at around 11.30pm on December 28, is being asked to call Calderdale CID via 101.
Information can also be passed on anonymously by calling CrimeStoppers on 0800 555111.