VIDEO : John Stamos Reveals How his Famous Catchphrase 'Have Mercy' Came to Be

During his acceptance speech at the awards ceremony, which taped last Sunday, Stamos admits that it was Garry Marshall, celebrated creator of Happy Days and winner of TV Land's Legend Award, who convinced him to coin a catchphrase.
"He always said, ?Get a catchphrase, you need a catchphrase.' I'm not kidding you. The ?have mercy' thing came out of, ?Oh s--t, Garry told me I had to have a catchphrase."
Stamos clearly has a lot of respect for Marshall, whom he credits for suggesting him for Full House.