Bat-Ochiryn "Ziggy" Ser-Od (Mongolian: ???-?????? ???-??, born 7 October 1981 in Gobi-Altai province) is a Mongolian long-distance runner who competes in road races, particularly the marathon.
He represented his country in the marathon at the Summer Olympics in 2004, 2008 and 2012 where he also was flagbearer.
A member of the Morpeth Harriers running club, he divides his time between his native country and Gateshead in England.
Ser-od began his international career in 2002 and has competed in the marathon at five consecutive editions of the World Championships in Athletics since 2003.
His best performance is 20th at the 2011 World Championships.
He is Mongolia's first ever elite level marathon runner and his personal best of 2:08:50 is the Mongolian national record.
He was the 2013 Asian Marathon Champion and also won the Brighton Marathon and Hofu Yomiuri Marathon in 2010.
Other career highlights include top ten finishes at the Berlin Marathon and London Marathon.