Police in Leeds say they are looking for a man dressed as a giant penis to help them with enquiries after an assault in the city centre.
The man is believed to have been part of a group, which officers suggest could have been a stag party.
The appeal was launched after a 26-year-old man was attacked by a white man, who is believed to have been with the same group, in the early hours of the morning on Sunday April 2.
Detective constable Gaynor Burt said that, while some might see the phallic costume as a joke, the nature of the incident is extremely serious as the victim ended up badly injured in the attack.
Burt said: "While the nature of costume worn by one of the group might be amusing to some, we are hoping that mentioning it will jog someone's memory and assist in tracing those responsible for what was a serious assault that has left the victim with long-term consequences.
"We have been making extensive enquiries to identify those involved and would like to hear from anyone who witnessed the incident or who has any information that could assist in tracing the group involved, who were possibly a stag party or similar.
"The costume worn by one of the group is very distinctive and we think anyone who encountered them during the evening would recall it."