Once you've said Oldbeard, you've said it all.
Hardassed, Unforgiving, and soft on the inside is a suiting description of his personality. Any cabinboy or low ranking shiphand will be more than eager to tell you tales of Oldbeard's relentless demand for perfection in his crew, how many fucks he gives about mistakes, and his hate for the pointing of fingers.
However, there is hardly a soul that knows of his sonnets and poems, and even less that know of his love for animals.
As far as you know, Oldbeard is the shell of he who was once known as Firebeard, the scourge of vessels everywhere, and the demon of the airways. Twas not a ship in the land that did not fear attack from Firebeard, and not a shiphand, first mate, or cutthroat that wanted to encounter the smoke breathing throatslasher that was Firebeard.
After having dissappeared for years, "firebeard" returned, aged, wizened, and much less ferocious. Almost all old feuds have been dropped, or laughed away. Hardly a soul would recognize him if not for the ship he still sails, the Chernobyl.
Now he is known as Oldbeard the pirate. If you're looking to get a good story though, or just something to marvel at and aim for as a pirate, get him a drink and ask him about the golden days of piracy.