Morn is a regular at Quark's. He is known for being really talkative. He is at the bar so much that he even has his own stool. The stool was almost made into a shrine when it was thought he was dead. He had an odd look but people like Jadzia Dax
found him attractive.
The producers of the Star Trek: Deep Space Nine television show created the character of Morn because they wanted to have a regular at Quark's Bar. They never intended for him to have a role they just wanted him to always be around. his name was modeled after the famous Barfly from the television show Cheers, Norm. They just switched the letters N and m from Norm and made him Morn.