Billionaire investor and former corporate raider, Carl Icahn has been very outspoken and a popular business news celebrity. However, very few books hav been written about him.
Probably the most thorough Icahn biography is King Icahn: The Biography of a Renegade Capitalist by Mark Stevens.
There is also Becoming Rich: The Wealth-Building Secrets of the World's Master Investors Buffett, Icahn, Soros by Mark Tier.
The Titans of Takeover by Robert Slater, profiles Carl Icahn, Saul Steinberg,T. Boone Pickens, and Ted Turner.
The book about corporate raiders, The Vulture Investors, Revised and Updated by Hilary Rosenberg includes Carl Icahn along with several other financiers.
In addition, there is Masters of the Universe: Winning Strategies of America's Greatest Deal Makers which writes a little about Icahn.
Finally, there is Wall Street People: True Stories of Today's Masters and Moguls by Charles D. Ellis.