The subject of this article or section is part of Darkmoon Faire, an ongoing event that lasts one week. Once the event has run its course, this will no longer be available until next month.
Carl Goodup is a level 20 balloon vendor located at Darkmoon Island, which is only available during Darkmoon Faire event. He walks up and down the lower half of the Faire.
He is probably a reference to Pixar's film Up and its main character, Carl, who makes his house fly using helium-filled balloons.