bell cow
n.— «Lamar wanted to bring in high school players that would learn under Tubbs for four years. They would become the foundation—what Tubbs’ refers to as “bell cows,” a group of leaders tutored on “Billy Ball.”» —“In the market for talent” by F.A. Krift Beaumont Enterprise (Texas) Jan. 22, 2006. (source: Double-Tongued Dictionary)