He was recognizable by his blonde hair, an eyepatch, and a dark suit. It is uncertain if he really has a religion, but he is shown making Harvey a bounty hunter in a very Jewish way in the episode Booty Noir. He has a habit of laughing whenever he says a double entendre or a non sequitur, followed by a short joke. He has numerous vision problems; it is implied that he is blind in the eye not covered by his eyepatch, and he states that he "sees everything 3 feet to the left" of where they really are, and must account for this fact. Throughout the series, Phil Ken Sebben is shown to be almost invulnerable to pain for in many episodes after suffering a terrible accident (such as falling down a tall building or dislocating his arms) he merely laughs it off and jokes about it. He has a daughter named Judy Ken Sebben who frequently masquarades as Birdgirl, with whom he is attracted to (not knowing that Judy is Birdgirl). He also constantly refers to himself as a "benevolent-ish dictator".
In the beginning of the episode Babysitter, Phil announces he's leaving the firm and starting his own law firm ("or spin off, if you will"), and how it will have a big S-shaped desk perfect for interviews, and that he would be far too busy to regularly appear, but that he will still be a contributor, or a senior correspondent ("... in law"). As he is about to give Birdman his final instructions, a bus hits him and his body vanishes. It is immediately assumed that he has died. For the next few episodes, Judy is given control of Sebben & Sebben via a will delivered by Phil's lookalike brother, Bill. During the series finale, The Death of Harvey it is revealed that Phil is actually still alive and was merely stuck to the front of the bus. He manages to tear himself off of the bus, commandeer it and drive all the way back to the office (in reverse). In the process of finally reaching Sebben & Sebben, Phil accidentally runs into Harvey, crushing him in the building. While mourning his death, the series ends with Phil having one final laugh and appropriately enough joking, "Last laugh."
The apparent death of Phil was written so his voice actor, Stephen Colbert, could be out of the series to start his show, The Colbert Report, which similar to Phil's stated job, is a spin off of another show, wherein Colbert interviews people, and broadcasts the majority of each show from C-shaped desk. Finally, Phil Ken Sebben appears and laughs "HA HA HA! Final episode stunt casting!", which is referring to Colbert's brief leave, and coming back for the final episode to voice his character again.
Stephen Colbert left the show during season 3, forcing the writers to remove Phil and Reducto from the main cast, though he briefly returned to voice Phil in the final episode. Colbert did not return to voice Sebben for the video game.
As revealed in the episode, Peanut Puberty (and others around it), Sebben has the ability to have his head turn 360 degrees.
Phil is a former Laff-a-Lympic athlete, who took the Silver for Judo in 1962.
He grew a mustache to cover up a scar caused by an accident involving a binder clip. He successfully sued the binder clip company, which gave him the funding to create Sebben & Sebben.
His around-the-world boat was named the Outrageous.
Phil seemingly married his own sister, "Aunt Phyllis" (whom visually resembles him to a disturbing degree) in Return of Birdgirl after almost marrying the Birdgirl-disguised Judy. Judy's own mother was never identified.
During the Episode "X Gets The Crest" Phil loses his eye-patch. While smoking a pipe, the tobacco smoke bellows from his empty socket. During the episode he replaces his eyepatch with a clear one that shows its shocking contents. Freeze framing when Phil passes under the X the Eliminator picture lets us see for a fraction of a second that Inch High Private-Eye is occupying the space where his eye should be.