He appears multiple times in the game, and defeating him is essential in completing the lost family quest. After retrieving all map pieces to the quests, he no longer appears, or becomes mentioned in the game. He uses a War Galleon in game, carrying 3000 gold. He uses a Cutlass in higher levels. One can also encounter him in a tavern if he's in a town. In this case, he has a special introduction cutscene, but otherwise, fighting him in a tavern is much like fighting an Annoying Captain or a Criminal (and, like in those two instances, the barmaid will smash a bottle over his head).
He has a black Georgian wig with a black mustache. His outfit is gold, dark blue, and white and wields a gun in fights later on. This "Evil Spaniard" wears the same uniform as a Spanish Sloop Of War captain with a morion and breastplate.