The California Supreme Court rules that Ted Giannoulas, better known as the man inside the San Diego Chicken suit, can appear publicly in chicken suits similar to the one that brought him fame, but not bearing the call letters of San Diego’s KGB radio station. The station had fired Giannoulas when he began appearing publicly in the suit without permission, and claimed it had all rights to the costume, which was first used as a promotional device in 1975.

On July 16, 1980 The California Supreme Court rules that Ted Giannoulas, better known as the man inside the San Diego Chicken suit, can appear publicly in chicken suits similar to the one that brought him fame, but not bearing the call letters of San Diego’s KGB radio station. The station had fired Giannoulas when he began appearing publicly in the suit without permission, and claimed it had all rights to the costume, which was first used as a promotional device in 1975.

Source
Baseball Reference July 16