And he is...?
Indra Nooyi's worst nightmare.
Ms Nooyi is already under pressure from Wall Street to turn round Pepsi after five lacklustre years of her chief executiveship, but the heat just got turned up further. Mr Whitworth, one of America's more aggressive activist investors, has started building a stake in the company.
He frightens boards of directors?
That he does. Over the years, he has pushed his way on to boards including at Genzyme, the biotech firm which sold itself, and Waste Management, where he shook out complacent executives.He learnt his terrifying trade at the knee of the veteran corporate raider T Boone Pickens.
But he's cute and cuddly in real life, right?
He likes a bit of flash. He surprised his then wife, Wendy, a producer for Larry King on CNN, with a 19-song concert by Paul McCartney at her 50th birthday party, for which he paid Macca $1m to give to charity. (Wendy detailed a "money no object" lifestyle of luxury homes and private jets in her divorce filing a year later.)
And at one point he had accumulated so many muscle cars that he was going to open an automotive museum in his home town in Nevada, featuring General Lees andrare Dodge concept cars,but the collection wentunder the hammer after the credit crisis.
What does he want from Pepsi?
"Constructive meetings" so far. But the issue hanging in the background at the fizzy pop firm is whether it should be broken up. It also owns Frito-Lay snacks, maker of Walkers Crisps, and some investors have started agitating for that business to be spun off. That sounds like just the sort of muscular action Mr Whitworth might demand at those constructive meetings.