Quite the character, apparently. Of note:
During his years as Detroit’s manager, Jennings became famous for his antics, mostly in the third base coaching box, which variously included shouts of “Ee-Yah,” and other whoops, whistles, horns, gyrations, jigs, and grass-plucking. The “Ee-Yah” whoop became his trademark and was accompanied with waves of both arms over his head and a sharp raising of his right knee. In 1907, he was suspended for taunting opponents with a tin whistle.
en.wikipedia.org/wiki/Hughie_Jennings
