Great-Grandfather Pegleg Addams is a deceased relative of The Addams Family.
He was the Scourge of the Seven Seas. The last of the adventurous Addamses, he was wanted by fifteen countries for piracy.
He was buried at sea with full military honors, handcuffed, blindfolded, and dropped off a plank. He never had a chance to pick up his treasure, or his insurance.
When Gomez and Morticia go through his sea chest, the find his sextant ("My, wasn't he the naughty one,"), pegleg (which he just wore for appearances), and a map to his treasure in the Sargasso Straits. There were a lot of treasure ships sunk there. Old Pegleg sank most of them. Morticia says he dropped the treasure overboard when he mutinied, though they later find the treasure buried under The Addams Family Mansion.
The Addams Family original series episode: