This weekend marks the return of the annual Boo! At the Zoo at Zoo Knoxville.

This year marks the 33rd year for the family-friendly Halloween festivities.

Each weekend in October, visitors can trick-or-treat along the boo trail where little trick-or-treaters can fill their bag with goodies as they make their way through the zoo.

This special event runs from 5:30 until 8:30 each evening.

Tickets are $9 for annual pass-holders and $10 per regular customer. Children 4 and under are free.