getListAuthor.js

function getListAuthor(listTitle,OnSuccess,OnError) {
    getListProperties(listTitle,
      function(listJson){ 
          var context = SP.ClientContext.get_current();
          var listAuthor = context.get_web().getUserById(listJson.Author);
          context.load(listAuthor);
          context.executeQueryAsync(
             function(){
                 OnSuccess(listAuthor);
             },OnError);
      },
    OnError);  
}


//Usage
getListAuthor('Discussion Board',
function(author){
    console.log('List created by: ' + author.get_loginName());
},
function(sender,args){
    console.log('Error occured:' + args.get_message());
}
);