Walnut City Mayor Mary Su, center, helps lead a flash mob at the annual Walnut Family Festival in front of Suzanne Park in Walnut on October 13, 2012. Participants practiced for weeks to surprise attendees of the festival.

Participants such as Adia Willemstyn of Pomona learned how to block attacks at a martial arts booth.

For more pictures of the parade, booths and entertainment see FESTIVAL.