Mickey Mouse greets fans in Chicago on November 15, 1978, as his cross-country whistle-stop train arrives at Union Station. (AP)

The public domain now includes the initial editions of Mickey and Minnie Mouse, over 95 years since Walt Disney first introduced them in "Steamboat Willie" on Monday.

The potential for diverse adventures awaits this iconic pair, as demonstrated by the changes that occurred when Winnie the Pooh entered the public domain last year.

Beginning from New Year's Day, any creator is legally entitled to utilize the characters in new works, specifically the "Steamboat Willie" versions and not the nearly century-long animated iterations.

It's noteworthy that Mickey and Minnie were initially set to enter the public domain in 2004, but Disney secured a 20-year extension by Congress.

On January 1, they will be accompanied by other properties such as "Lady Chatterley's Lover" by D.H. Lawrence and "The Circus" directed by Charlie Chaplin, as per a compilation by Jennifer Jenkins, director of the Duke Center for the Study of the Public Domain.

Mickey Mouse in "Steamboat Willie." 1928. (AFP)

The United Kingdom has its distinct copyright regulations with differing expiration dates. Disney has encountered the prospect of losing copyright protection for its original cartoons on multiple occasions.

Initially anticipated to enter the public domain in 1984, the characters received a 20-year extension through a Congressional decision. Subsequently, as the expiration date in 2004 approached, another 20-year extension was granted.