A man was assaulted in a nightclub in Halifax by a man dressed as Batman.
The victim was in Chicagos on Commercial Street between midnight and 2am on Sunday when the attack happened.
He was hit on the back of his head.
Police are urging anyone who knows who the man dressed as Batman was or who saw the assault to call Detective Constable Delia Lenihan in Calderdale CID on 01422 337085 or via 101.
Information can also be passed on anonymously via Crimestoppers on 0800 555111.