Underland by Mick Farren
Victor Renquist, centuries-old Nosferatu colony Master has been co-opted by the paranormal branch of the National Security Agency. Their mission: to rout out survivors of Hitler's Third Reich who have set up a secret base in Antarctica. But the Nazis have some very powerful allies - the Dhrakuh, a race of sentient reptiles from the dawn of time. With the doubtful aid of Jack Coulson, an NSA hardline operative, and Thyme Bridewell, a failed NSA brain-control experiment, and hampered by some throwbacks from his own race, Renquist is pushed to his limits as he struggles to save the world.