BOO! at the Zoo presented by U.S. Cellular kicks off Knoxville’s largest Halloween event now through Oct. 23. Knoxville’s largest Halloween event features 12 nights of safe and not-too-scary fun scheduled over three weekends; Thursday through Sunday, Oct. 6-9, and continuing Thursday through Sunday, Oct. 13-16 and Oct. 20-23, from 5:30-8:00 p.m. each evening. BOO! at the Zoo, a Halloween tradition for 30 years, is a family event featuring trick-or-treating through the zoo along the BOO! Trail, the Chick-fil-A Monster Mash tent with fun that’s perfect for preschool and elementary-aged event-goers, friendly costumed characters and entertainers throughout the zoo, and the only “haunted” carousel in East Tennessee, the Scary-Go-Round. (How can you tell it’s haunted?