What’s so different about the puppet comedy “Greg the Bunny” (8:30 p.m., Fox)? On “Greg” the puppets are real. All too real. But don’t even think about calling them puppets. They consider themselves “fabricated Americans.” They’re living, breathing entities, capable of thoughts and emotions. And on “Greg” most of these thoughts run towards neurotic, backstabbing behavior.

“Greg” lives with his human best friend Jimmy Bender (Seth Green, “Austin Powers”) who happens to be the slacker son of Gil Bender (Eugene Levy, “Best in Show”), the director of the long-running kids’ television show “Sweetknuckle Junction.” Greg gets his big chance when a scheming network executive, Alison Kaiser (Sarah Silverman), forces Gil to fire their aging rabbit star and replace him with younger and cuter talent. Impressed by Greg’s natural ease (and completely unaware of his lack of acting experience) Gil and Alison hire him on the spot.

Once ensconced at “Sweetknuckle” Greg joins his fellow puppets, including Count Blah and Warren “Professor Ape” Demontague and human co-stars Dottie Sunshine (Dina Waters) and Junction Jack (Bob Gunton) in backstage bickering and ego trips.

While the scenes at “Sweetknuckle” offer a perfect send-up of kids shows, from “Captain Kangaroo” to “Sesame Street,” this comedy’s real strength lies in the completely believable chemistry between Greg and Jimmy, as well as Gil’s fawning relationship with his network masters. Levy should be comfortable in this role. He was part of the brilliant ensemble cast of “SCTV,” set at an absurdly cheap network. “Greg” is a real winner: silly, occasionally raunchy and always laugh-out-loud funny.

 Buffeted by vanishing viewership, ABC may be wise to play it safe. Two of the network’s sitcoms, “My Wife and Kids” and “According to Jim,” have succeeded by turning to familiar formulas, laugh tracks and production values. Add “George Lopez” (7:30 p.m., ABC) to this list. Lopez, a stand-up comedian, stars as an assembly worker at a Los Angeles airplane parts factory where he must contend with a rowdy work force that includes his overbearing mother (Belita Moreno, “Perfect Strangers”).

 Set in the world of network television, the dreadful and unoriginal “Wednesday 9:30” (8:30 p.m., ABC) is the third sitcom to recycle the same mean-spirited joke. A few years back, the funny Showtime comedy “Beggars and Choosers” featured a black female executive in a wheelchair. She called herself “an affirmative action triple threat.” Last Fall, “The Bob Patterson Show” featured a clumsy, incompetent, wheelchair-bound black woman who couldn’t be fired. And tonight on “Wednesday,” an up-and-coming black female executive brags that nobody can dismiss her, and the only thing she fears is the sight of a “black woman in a wheelchair.” Considering that comedy writers can make tens of thousands of dollars per week, you would think they might come up with some original gags.

Tonight’s other highlights

 Scheduled on “60 Minutes II” (7 p.m., CBS): A high-ranking military officer tells why he betrayed his country; Shanghai’s innovative architecture.

 Pirates board the ship on “Enterprise” (7 p.m., UPN). Guest starring “Deep Space Nine” favorites Ethan Phillips and Jeffrey Combs.

 Bernie tries to discipline his nieces and nephew on “Bernie Mac” (8 p.m., Fox).

 An outspoken poet laureate (guest star Laura Dern) causes concern for Toby on “The West Wing” (8 p.m., NBC).

 Greg Gumbel narrates “The March to Madness” (8 p.m., UPN), a look at the NCAA Men’s Basketball tournament.

 Parents and teachers discuss new strategies for students with learning disabilities in the news special “Misunderstood Minds” (8 p.m., PBS). Hosted by Chris Bury of “Nightline.”