Wynchel and Duncan are characters from the video game, Sugar Rush Speedway, where they serve as the primary security forces for the kingdom's ruler. They are quick to violence, immediately bashing Wreck-It Ralph in the head with their batons even after the bad-guy was trapped within a giant cupcake, making it incredibly difficult to move.
Even so, they take their positions very seriously and prove to be rather persistent. As shown in the spin-off comic, The Donut Kart, they seem to have very little patience, considerably Wynchel, and are sometimes prone to bickering with one another.
Wynchel and Duncan are King Candy's muscle, ensuring order in the Sugar Rush community. Just don't make 'em mad or their frosting might melt.
When Vanellope von Schweetz, a young girl who was banned from racing in Sugar Rush because she's a glitch, weasels her way into the Random Roster Race, Wynchel and Duncan are called fourth to arrest her, but a taffy monster interferes and scares the donuts away. The distraction allows Vanellope to escape, while the taffy monster gets itself stuck in a giant cupcake, allowing Wynchel and Duncan to capture it and take it to King Candy. There, the monster is revealed to be Wreck-It Ralph, who was looking for his medal that Vanellope stole.
King Candy tells him that it's impossible to retrieve his medal because she deposited it in the codes along with the other gold coins, which now allows her to race. Wynchel and Duncan are then ordered to escort Ralph out of Sugar Rush, but Ralph escapes and searches for racers to win back his medal. Later on, Wynchel, Duncan, and King Candy head to the kart factory where Vanellope and Ralph have broken in to make a kart. On their motorcycles, Wynchel and Duncan chase Ralph and Vanellope down but they lose them.
King Candy orders the duo to continue searching, but after a while, Wynchel and Duncan return to the castle to inform the king that they've failed and King Candy ordered them to leave. Later on, Duncan can be spotted escaping Sugar Rush during the Cy-Bug invasion caused by Ralph accidentally bringing a Cy-Bug from Hero's Duty into Sugar Rush. Thanks to Ralph, the Cy-Bugs were defeated, as was King Candy, who turned out to be a rouge video game character who dominated Sugar Rush, dethroning Vanellope who is the game's true ruler. Fortunately, Vanellope is revealed to be the "Princess of Sugar Rush", but decides to make herself president instead. After the truth was revealed, Wynchel and Duncan apologized to Vanellope and gladly became her security guards.
Wynchel and Duncan then have a final appearance during the end-credits sequence; apparently participating in game-jumping adventures like the lead characters, the duo is glimpsed running from Cyril the Zombie (with a few more zombies) chasing them.