Harley Clark, the head cheerleader known for making popular the famed "Hook 'Em" hand sign back in 1955, died Thursday morning at age 78, The Alcalde reports.

Clark is survived by his wife, four daughters and five grandchildren. He was active in Texas Exes throughout his life.

The Alcalde recounts how Clark introduced the iconic gesture.

"With crimson hex candles burning in storefronts and homes around Austin, students paraded across campus to Gregory Gym, where, after a revival-style fundraising show, Harley Clark and the Texas cheerleaders pumped up the crowd for Saturday’s game.

Then Clark did something unplanned. He lifted his hands in the now familiar gesture—one suggested to him days earlier by classmate Henry “HK” Pitts, BA ’56, Life Member, and told the crowd it was the new, official hand sign of the university.

That’s what had [then-Dean Arno Nowotny] fuming. Clark responded that he was only 19 years old, and no, he didn’t know it was an offensive gesture in Italy.

'Just be glad we’re not the unicorns,” Nowotny responded. But there was nothing he could do. The next day, a stadium full of Longhorn faithful lifted their horns up, and the rest, of course, is history."

Here's the Full Story on Harley Clark's Passing