The Chicago Cubs are claiming in a lawsuit that an unofficial mascot called “Billy Cub” is giving the team a bad name.

The lawsuit accuses the mascot of hustling fans for fees and tips outside Wrigley Field without permission of the ballclub and in violation of trademark laws. The Cubs also contend the bogus mascot is causing confusion with its new official “Clark the Cub” mascot.

The Chicago Sun Times reported on the lawsuit Friday, saying the case was filed in the federal court in Chicago against  John Paul Weier, Patrick Weier and three other unidentified individuals who have all dressed up as Billy Cub before games.

The Billy Cub character is a bear wearing a Cubs baseball cap and a Cubs gray jersey with No. 78 on the back.

According to The Sun Times, the lawsuit states the character has made “rude, profane and derogatory remarks and gesticulations to patrons, ticket holders, fans or other individuals located in the area of Wrigley Field.”

The lawsuit also says the Billy Cub mascot has generated negative publicity by getting into bar fights.

The Sun Times said the Weiers could not be reached for comment.