They are two childhood friends named Kelly. Now they share one mission: Raise $25,000 for Boston Children’s Hospital, where each has a child under care. Kelly Sheehan Catallo and Kelly Granara South have organized The Running of the Leprechauns, a 5-kilometer run/walk to be held on March 16, 10:30 a.m. at the Medford Elks, 19 Washington St. A St. Patrick’s Day party will follow at the Elks. Registration costs $30, and the first 300 to sign up will receive a T-shirt and gift bag. The cost to attend the party only is $25. For information, visit www.facebook.com/RunningOfTheLeprechauns.