Estelle Leonard of The Estelle Leonard Talent Agency is Joey Tribbiani's withered, chain-smoking acting agent.
She hired him after seeing "Freud!", a low-budget musical that Joey played the lead in. Despite being slightly bemused when he idiotically spilled a drink on her shortly after they met for the first time, they seemed to get on reasonably well throughout the course of the show. Although she did get Joey his breakout role as Dr. Drake Ramoray on the NBC soap opera Days of our Lives, she was not very good at her job for the most part; most of Joey's screen roles were as extras with minimal - if any - lines, and even offering him parts in gay porn. Once she even mistakenly thought Joey had left her and tried to sabotage his career, when, in fact, he was still her client.
Amongst Estelle's other clients were an act with a 'pyramid of dogs' and Al Zebooker, a man who eats paper. Estelle died during the tenth season (of a coronary embolism according to her obituary), just before the series finale. At the time of her death, her only two remaining clients were Joey and Al Zebooker. Because Phoebe was worried about how Joey would take the news (since so much of his personal life was changing at the time) she impersonated Estelle until Joey found out about her death. Unfortunately for Phoebe, shortly after Joey received news of Estelle's death (from Zebooker), Phoebe called him and impersonated her once again, giving Joey the impression that he had received a message from beyond the grave.
Estelle Leonard is a reference to one of the founding sisters of Alpha Chi Omega.
June Gable also played the nurse in The One with the Birth (Season 1 Episode 23) when Ross' son, Ben, is born.