Plot: Lisa's science fair project is overshadowed by Bart's mechanical baby seal; Homer's new assistant ends up stealing his job.
Cast
Dan CastellanetaHomer Simpson / Abe Simpson / Barney Gumble / Krusty (voice)Dan Castellaneta was 54 in The Simpsons - Season 23 - Replaceable You (Episode 4).
Birthday: Tue, Oct 29 1957
Julie KavnerMarge Simpson / Patty Bouvier / Selma Bouvier (voice)Julie Kavner was 61 in The Simpsons - Season 23 - Replaceable You (Episode 4).
Birthday: Thu, Sep 07 1950
Nancy CartwrightBart Simpson / Nelson Muntz / Ralph Wiggum (voice)Nancy Cartwright was 54 in The Simpsons - Season 23 - Replaceable You (Episode 4).
Birthday: Fri, Oct 25 1957
Yeardley SmithLisa Simpson (voice)Yeardley Smith was 47 in The Simpsons - Season 23 - Replaceable You (Episode 4).
Birthday: Fri, Jul 03 1964
Hank AzariaMoe Szyslak / Chief Wiggum / Apu / Comic Book Guy / Carl (voice)Hank Azaria was 47 in The Simpsons - Season 23 - Replaceable You (Episode 4).
Birthday: Sat, Apr 25 1964
Harry ShearerNed Flanders / Mr. Burns / Smithers / Skinner / Lenny (voice)Harry Shearer was 67 in The Simpsons - Season 23 - Replaceable You (Episode 4).
Birthday: Thu, Dec 23 1943
Jane LynchRoz Davis (voice)Jane Lynch was 51 in The Simpsons - Season 23 - Replaceable You (Episode 4).
Birthday: Thu, Jul 14 1960
Crew
Mark KirklandDirectorMark Kirkland was 54 in The Simpsons - Season 23 - Replaceable You (Episode 4).
Birthday: Thu, Nov 15 1956
Stephanie GillisWriterStephanie Gillis was 42 in The Simpsons - Season 23 - Replaceable You (Episode 4).
Birthday: Thu, Oct 02 1969