|This article or section is about elements from the Baldur's Gate: Dark Alliance series of games.
Video games are considered canon unless they contradict content in some other Forgotten Realms publication.
Ethon was a human patron first met in the Elfsong Tavern owned by Alyth Elendara in Baldur's Gate. He is the second character the trio speak with after their attack out on the city streets outside of the tavern. 
Ethon was once a thief. He admits to being one after his rescue in the sewer dungeons beneath Baldur's Gate. He describes how he was part of Baldur's Gate original Thieves Guild many years before and that he retired to lead an honest life. It is also mentioned by Alyth, that Ethon was the one who found a Beholder in the cellar. It was later stuffed and displayed in the tavern.
Ethon provides help to the trio, beginning with his willingness to lend the trio the cellar key during the first mission. For the trio's first mission, Ethon gives them his rusty dagger (inherent to his former occupation as a thief) He later is captured after he sought to follow the trio into the cellar. He is then held prisoner by Kobolds and their Bugbear chieftain until the trio defeats them and frees Ethon. He then mentioned a secret entrance into the sewers from the street level and apologizes for not having told the trio about it sooner as he hoped the rats would discourage them from entering the cellar or the sewers. Afterwards, he provides a second key to the trio, explaining how he picked it off the chieftain that captured him. Before he returns to the Elfsong Tavern, Ethon tells the trio some information and offers further help by contacting old associates from his thieving days.