We introduce you to the mascot race, London Series style. King Henry VIII, Winston Churchill, Freddie Mercury and the Loch Ness Monster do a test run at London Stadium. (0:45)

The London series between the New York Yankees and the Boston Red Sox will feature a giant mascot race with a British spin.

Winston Churchill, Freddie Mercury, King Henry VIII and the Loch Ness Monster will race around the warning track at London Stadium. The four were chosen by fans who voted on four categories of notable Brits -- cultural icons, legends, historical figures and monarchs.

Mercury beat out William Shakespeare and John Lennon in the voting.

Prince Harry, the Duke of Sussex, will attend Saturday's opener and will accompany competitors from the Invictus Games onto the field to throw out the first pitch.

The Kingdom Choir, which stole the show at the Royal Wedding of Prince Harry and Meghan Markle in 2018, will perform the national anthem on Saturday.

About 1,500 invited fans attended batting practice Friday. Movie director Spike Lee walked around in foul territory, while the grounds crew performed to the Village People's "YMCA," as they do in the Bronx. Delaware North, the stadium food contractor, brought over George Raub, a 39-year-old from Georgia, to teach staff how to hawk food in the stands.

"It's all about showmanship and bringing them outside of their shell," Raub said. "Joked a little bit: If they've ever wanted to be a West End actor here in London, this is their chance to really showcase their skills."

Players from both teams relished being able to do some sightseeing around the city without being recognized.

Yankees slugger Aaron Judge said he walked near the London Eye and reliever Chad Green toured the Churchill War Rooms under the streets of Westminster. Boston outfielder Mookie Betts played golf and ate with his family at Borough Market, while Rick Porcello and Red Sox teammate Brandon Workman went to Camden Market, Shoreditch and Piccadilly Circus.

"I was actually walking near the London Eye yesterday, and I ran into a couple people that had the Yankee hat on," Judge said. "They had no idea who I was or anything. I said this is all right. 'I'm Aaron, great to meet you.'"

Boston manager Alex Cora and Yankees counterpart Aaron Boone went to Buckingham Palace for the changing of the guard, and Cora visited Kensington Palace. A gala was scheduled for the Tower of London.

The Associated Press contributed to this report.