The 15th annual "Ghouls at Grassmere" is set to begin at the Nashville Zoo on Thursday. The event, which features more than 20 trick-or-treating stations, animal shows and costume parades, will be held Thursday through Sunday and October 25 through 28 from 5 p.m. to 8 p.m. each night. Guests can also go on a Haunted Hayride through the zoo or go for a ride on the Scary-Go-Round among other activities. "Ghouls at Grassmere" is $12 for zoo members and $15 for non members. Ticket prices include all activities, rides and parking. Tickets purchased before Thursday will receive a $2 discount. Tickets can be purchased at NashvilleZoo.org or at the zoo's guest services each day before 3 p.m. The Nashville Zoo attracts more than 640,000 visitors each year.