Simplify the following text for a Grade 10 native English-speaking person.
Original: Harvey Birdman , Attorney at Law is a Adult Swim program that stars Birdman who started out as a super hero on the Hanna-Barbera program Birdman and the Galaxy Trio and is now a lawyer for Sebben Sebben .
Simplified: Harvey Birdman , Attorney at Law features ex-superhero Harvey T. Birdman of Birdman and the Galaxy Trio as an attorney working for a law firm alongside other cartoon stars from 1960s and 1970s Hanna-Barbera cartoon series .