Dorchester-10/27/2012-. Waiting in line for a hay ride, (left to rt) Jkhia Bullock, 7, Tahje McBride, 4, and Allisa Johnson. 7 all from Dorchester are dressed for the occasion. Hundreds of costumed kids and adults showed up at the Franklin Park Zoo for the annual Halloween Zoo Howl which runs through Sunday October 28, 11-3pm. A best costume contest is held at boon. Globe staff photo by John Tlumacki(metro)