Of course Icke is a plant..
Anybody who mixes genuine criticism of the Federal Reserve (in Chapter 3) alongside Shape-Shifting Lizard People (in Chapter 4) *has* to be on CIA payroll.. This is precisely how the Establishment discredits legitimate criticism of its activities (by juxtaposing those criticisms next to outlandish claims like Icke's ... so that if you go out in the real world and try to educate people about the Fed, the public will think you *must* believe in lizard people as well).. :-P
The reptilian theory is an amalgamation of different theories.
Most religions/cultures talk about the Great Flood, where civilization was wiped out and started over. There APPEARED TO BE human hybrids running amuck (in the Bible, the 'fallen ones' mated with earth women who produced the Nephilim, "the men of whom legends were made of").
Icke merely pushes the envelope to the limits. As far as credibility in the eyes of the sheeple goes, I make it a habit to carry around evidence (articles, photos, videos, etc.) in case anyone wants to dispute me. Even then, I'm still a nut.