Rambo, a Bronx homicide detective, changed out of his sweat suit and into a Con Ed employee uniform. Hulk’s choice of a disguise was appropriate: gas leaks, like fires, were common in the neighborhood. That morning, a tip had come in … Hulk and the other undercovers drove to Anthony Avenue. …
Rambo, nicknamed for his pumped-up body, was known for solving cases.
So which is it? Hulk? Or Rambo? It’s pretty clear from context that we are only talking about one person. I suspect the real nickname was “Hulk” as the Hulk is known mainly for being big & beefy, whereas Rambo is known mostly for being a loner and revenge-o-phile. But who knows. Maybe we have the author to thank for both.
source: Random Family: love, drugs, trouble, and coming of age in the Bronx by Adrian Nicole LeBlanc