In the Original BSG the Cylon race was Reptilian and created the cylon robots as workers but then the mechines turned on their masters and wiped out most of the race save a few thats where the Imperious Leader comes from all be it he is a high bred, in the Galactica 1980 series the cylons had created a few humanoid cylons.
In the reimagined series is where the humans created the cylons as robots to serve them but they rebeled and that was start of the first cylon war then the cylons disappeared for many years and then when they came back they were humanoid.
hope that helps
Just want to throw my $0.02 in here and add that all of the Imperious Leader scenes we see in TOS are not actually the original Cylons, but are IL-series Cylons (like Lucifer and Spectre) that have been elevated to the "post" of Imperious Leader. We can derive this from some tidbits dropped in the show:
1. When Count Iblis meets with Baltar, he mentions that his voice was encoded to be the voice of Imperious Leader, which Baltar remarks happened over 2000 yahren ago. Now, this is a nod to the fact that Patrick McNee *did* supply the voice of Imperious Leader, but the fact that he mentions that it's his voice that's used by the Imperious Leader suggests that Imperious Leader himself is a machine.
2. In the first episode of the series, Imperious Leader tells Baltar he is to be spared because he, unlike his predecessor, was *programmed* in a more tolerant time, and could afford to show mercy.
3. IL-series..."I"..."L"...Imperious Leader....hmmmm...
I remember reading - maybe in the novelization? - that the original Cylons had three brains, and that Imperious Leader was supposed to be one of the few remaining reptilian Cylons left. The fact that the bubblegum cards show a close-up of a very reptilian face, not to mention the action figure is squarely organic, supports the theory that some organic Cylons were left around.
But I agree that ABC probably threw a hissy over this and made Larson change certain details from Saga to the series (including the infamous profession change for Cassiopeia). The reason I believe that Imperious Leader is a IL-series is based on dialog from Young Lords where, IIRC, Baltar makes an offhand comment about Spectre's performance that he could potentially be in line for Imperious Leader, as well as a close-up of Imperious Leader's procession on Molokai in Living Legend Pt 2 where his "afro" is see-through and it looks (at least to me) like an IL-series head underneath. Now maybe this was them cheaping out on the special effects, but given that this was one of the few episodes that had sufficient star power to get stuff done the way they wanted, I doubt it.
(I recall an anecdote about ABC getting so cheap that they wanted the cast to start paying for Kraft Services. Messers Greene and Bridges were so livid that they both marched in to the president of ABC's office to give him a piece of their mind. I don't know specifically what was said, but the Kraft Services table went back to being gratis.)
You can find it on the battlestar wiki plus I read it years ago in a starlog magazine which I may still be able to get my hands on
Actually, you're all right in the origin of the Cylons.
In BSG: TOS the Cylons were reptilian and they developed the robotic in three basic categories. 1)The Centurion -Silver: Warrior/Pilot, and Gold: Commander. 2) The I.L. Series - Lucifer. 3)The Imperious Leader. There was a fourth series not mentioned, but seen on TOS 2-part episode The Living Legend that seemed to depict a "civilian" category of robotic Cylon. Now, on the Glen Larson BSG books your standard Cylons had 1 brain, I.L.-Series had 2, and the Imperious Leader had... well, 3. Go figure. (Not sure if the Imperious Leader was a Cyborg, hybrid, or otherwise). Between BSG canon and FanFic there's been many interpretations, oppinions and speculations; but, most of what had been discussed - like all rails leading to Chicago - points in the right direction. The same probably wold apply to their reptilian predescessors. The Cylons carried their masters' original plan: Universal domination. They did attack the Hasari, and their neigbors from the 12 Colonies of Man came to their aid thus begining the "Thousand Yahren War".
On SyFy's rendition MAN made the Cylons, yes. If CAPRICA hadn't been cancelled (thanks to low ratings) the reimaged's version would have likely cleared out any doubts or speculations as to how the rebellion started. This man vs machine war was much-much shorter and the Cylons were shoved into the depts of space.
However, I do have a bone to pick about Ron Moore's idea of the infiltrator version of Cylon: their cyborg series, that is. For one, I'm surprised that TERMINATOR's James Cameron didn't sue him for plagerism behind cyborgs killing people. Or, Riddley Scott for the use of the term "Skin Jobs" which was originally used on BLADE RUNNER. Granted, Moore has every right to tell his version of the BSG story, but to some Science Fiction buffs that doesn't sit too well. Needless to say, "his plan" worked. Everybody watched the show and it kept us glued to the tube (or flatscreen) on every season.
Now, on BSG:1980 there were a few Cylons which were human in appearance; but, they were NOT cyborgs. Instead, they were prototype-Androids.
Anyway, there's going to be many discussions and arguments about this subject... no doubt about it. I just wonder what Bryan Singer's take is going to be on this when his BSG project is complete.