Aired pilots that were greatly different from the eventually aired show

My friends were discussing Forever Knight, and I told them that I had seen the pilot movie that had all of the same main characters played by different actors, including Rick Springfield as the title character “Nick Knight”. Are there other aired pilots that are vastly different from the shows that were eventually broadcast?

Probably most famously Star Trek had two. The first one was the Jeffrey Hunter episode Captain Pike. The second one with Marjel Barrett as the executive officer and a smiling Spock.

Aired pilots only, please.

Both the Star Trek pilots were aired. The first one was altered when originally aired the second pilot was aired as episode three which didn’t make much sense.

Let me try to clarify: I am talking about when the pilot for a series airs, then later a show based on that pilot, but is substantially different from that pilot in some way, airs.

Nevermind
(not really what the op wanted)

.11 TV Pilots That Are Drastically Different Than The Show You Know

I saw The Seinfeld Chronicles.

Not quite correct.

All of these details are true of The Cage, the first pilot - later edited into the 2-parter The Menagerie.

The second pilot, Where No Man Has Gone Before, had already discarded Barret’s Number One, and promoted Spock (as well as giving him Number One’s emotionless mien).

The pilot for Cagney and Lacey featured Loretta Swit as Cagney. When they opted for it as a show, they had Meg Foster as Cagney. Then they went with a third actress playing Cagney after the first season, Sharon Gless.

Wasn’t the change to Gless because the studio didn’t think Foster was “feminine” enough?

Danny Williams was played by Tim O’Kelly in the Hawaii Five-O pilot “Cocoon.” Test audiences apparently didn’t care for him, since he was replaced with James MacArthur once CBS bought the series.

Lew Ayres was “The Governor,” a role that would later go to Richard Denning.

I’ll say

In a shockingly candid (and also gross) interview with TV Guide at the time, an anonymous CBS executive explained their reasoning, noting that the stars were:

[T]oo tough, too hard and not feminine. They were too harshly women’s lib. The American public doesn’t respond to the bra burners, the fighters, the women who insist on calling manhole covers ‘people-hole covers.’ These women on “Cagney & Lacey” seemed more intent on fighting the system than doing police work. We perceived them as dykes.

Happy Days premiered as an episode of Love American Style. There was no Fonzie, I don’t think there was a Ralph Malph (Haven’t seen it in a while), Richie and Potsie were a lot less kid-friendly, Joanie was a different actress, and older brother Chuck was a fairly important character.

Do we consider the pilot for The Simpsons to be its first episode or its trial run on The Tracey Ullman Show? They are very different.

For varying degrees of “greatly”:

Ib the pilot episode fopr The Magician, Bill Bixby’s character was namesd Tony Dorian. When the show got picked up he became Tony Blake.

In the Magnum PI pilot, Rick had his own club, called Rick’s Cafe Americain, and affected this Rick Blaine/Bogart persona. He did keep the name - I guess if I were christened "Orville Wilbur Wright’, I’d find a nickname, too,

It should also be noted that the second ST: TOS pilot differed in many ways from the series that followed. The uniforms were different, the instrumentation was different, the bridge was different. There was a male communications officer, and the Yeoman was Gary Mitchell’s love interest, not Kirk’s. There was Dr Piper instead of McCoy. The phaser rifle was seen for the first and last time, and Piper dispensed pills, not hypo-sprays. And neither Shatner nor Nimoy had nailed their characters yet.

I’m sure there were other points of difference, but these are the first that come to mind.

NCIS was introduced in two episodes of JAG. If memory serves me correctly in the first aired episode the Jethro and Tony characters had different personalities than in the rest of the series.

I never saw Forever Knight mentioned in the OP, but of the other cases mentioned or linked I’m only seeing recasting and character refinement as the changes. None of them seem to be all that great or drastic after an aired pilot.

I saw a rerun of the pilot after I had watched the series for a while. I remember Jethro and Tony heading to their first crime scene in the forensics van. They were cracking jokes and laughing, which amazed me. I was used to seeing Gibbs as a real hard-ass boss.

Sorry I confused a couple of things. Where No Man Has Gone Before was filmed as the 2nd pilot but aired as the 3rd episode which makes for some bad continuity problems. Bones had already been established as the doctor in two episodes and then Paul Fix is the doctor in this one then never to be heard from again. Also the interior of the Enterprise is different, the uniforms aren’t quite right, and there are some crew members that seem important who don’t ever return. But I did confuse Marjel’s role with what she did in The Cage.

I saw the first Big Bang Pilot, in Italy. In it both Sheldon and Howard were smitten with Penny.if I remember correctly she was a brunette. The othe characters weren’t introduced.

They aired it in Italy as a pilot? Interesting.