And Morgan Fairchild as his mother. Their names were Charles and Nora.
She showed up fairly early though–the eleventh episode of the first season, according to IMDB. Before the midway point of the first season isn’t exactly later in the series; I’m not sure she was even mentioned before that.
Airwolf’s first several seasons made reference to Stringfellow Hawke’s long-lost brother, St. John (pr. sin-jin). The latter finally showed up in the fourth season (exit Stringfellow, enter St. John).
I could never decide whether I’d prefer the name Stringfellow or St. John. Probably neither.
I thought they missed a good opportunity to have Vera show up for the last show and have her be drop-dead gorgeous.
This is kind of minor, but in the Wire season three we get to hear a lot about a certain Eunetta Perkins. It is the woman that Marla Daniels is campaigning against. However, it takes until the final episode of the season for her to actually appear on screen.
If I recall, Buddy Sorrell’s wife Pickles was mentioned quite often, but never seen until later on in the series.
No, he was first seen at the end of season 5, but he was definitely not mentioned early in season 1. IIRC, first possible mention would be when “Henry” mentions something about the Others being led by a great man late in season 2, but the name Jacob wasn’t mentioned until some point in season 3, and even then at first it’s just seen flashing in the brainwashing movie being shown to Alex’s boyfriend (God loves you as he loved Jacob) at which point it could’ve easily been mistaken for a Biblical reference rather than as a reference to leader of the Others.
OFF TOPIC NITPICK
There is only one series of Lost, and it lasted 6 seasons.
When speaking of television shows, the British use series as we use season. They use show as we use series (and, um, show).
Next you’ll be objecting to the words lorry and petrol.
Perhaps a feral sheep?
Tony Soprano’s older sister Janice was seen only in childhood flashbacks (like his younger sister Barbara) until she became a major character in the second season.
Nice catch! I had no idea. 
No, Lars was killed off before he was ever seen.
On Empty Nest, there was a third youngest daughter named Emily, that was away at college and wasn’t seen. After Kristy McNichol left the show, they brought her in temporarily to fill the gap.
IIRC lorry is what they call an elevator and petrol are the mineral droppings that drip from the top of the queen downward.
Laverne’s husband, a minor league ballplayer whose description was that of a Hee-Haw character, was often referred to but unseen until he became a recurring character in later scenes.
I’m going to have to release the lemmings on you for this. It’s not personal.
Wow… that’s… not what I expected.
Speaking of Cheers, there were references to Mrs. Clavin in the early years, but she doesn’t appear on screen (played by Frances Sternhagen) until the fifth season. We did hear his mother’s voice before that, but I don’t know if Sternhagen played her then.
On The Drew Carey Show, Drew’s original boss, Mr. Bell, was only heard via intercom but never seen for ages. Then he got fired and came out of his office for the first time carrying his stuff in a box (in the person of Kevin Pollack) and snarled something like “What’s your problem, Carey? You’re acting like you never saw me before!”
To elaborate: Pickles didn’t appear until Season 1, Episode 13, and after Season 2 was not seen again. She was played by 2 different actresses. Pickles had 5 appearances altogether.
I seem to recall that Cockroach didn’t appear on The Cosby Show until quite late in the game, after numerous mentions of him by Theo.
Yeah me either. I thought we had seen him from behind and he had been wearing a helmet or something. Or that he looked like Rupert Everett.
I think Jacob is fair for Lost. By the time he showed up, the show had us convinced he was a con of Ben’s…