Jeff Dunham, the comedian ventriloquist who has sold more tickets at the Great Allentown Fair than any other comedy artist performing on the Fairgrounds Grandstand stage, is back for the fourth time with his zany cast of characters, 8 p.m. Sept. 4. Dunham broke records at the Fair in 2009 when he sold 19,000 tickets for a two-night stand. The Fair audience so embraced his colorful characters, including grumpy old Walter, José Jalapeño on a Stick, Peanuts and Bubba J, that Dunham was invited back in 2010 and 2013. Dunham, a fixture on Comedy Central, holds the record for viewership on that network, has sold more than 7 million DVDs worldwide and has been viewed nearly a billion times on YouTube. He starred in an NBC-TV special in fall 2015 following a nearly year-long residency at Planet Hollywood, Las Vegas.