Marl is a grumpy drunk found in Feldepost's Inn.
He doesn't like adventurers because he blames them for his son's death. His son, Kennair Nethalin, aspired to be an adventurer but died doing so.
You can slay him without losing any Reputation, or calm him down for a significant experience reward.
|“||I'm sick of you freakish adventurers going out, consorting with gods know what, and dragging your trouble back into my hometown!||”|
- In original Baldur's Gate, you could talk him down and then kill him anyway at no penalty, for the 650 combat XP. In various fixpacks and Enhanced Edition, this trick no longer works, though you can still kill him after talking him down.