Survivor Sumo (also known as Sumo at Sea, Kung Fu Cannibals and Sumo in Mud) is a recurring challenge that originated in Survivor: Palau and was used in later seasons.
One member from each tribe faces off on a platform surrounded by either water (Palau, Blood vs. Water, and San Juan del Sur) or mud (Fiji and Heroes vs. Villains). Using their padded bags, or any other body part other than their hands, they must try to knock each other off the platform. Doing so would score their tribe a point. The first tribe to reach a certain number of points would win.
The challenge reappeared as a Reward Challenge in Survivor: Fiji. Moto won, taking home fishing gear, toiletries, coffee and potatoes.
The Heroes won this challenge in Survivor: Heroes vs. Villains in a blowout. In addition to Immunity, the tribe also won rice, sugar, coffee and the tribe's luxury items.
The challenge appeared again in Survivor: San Juan del Sur as the second Immunity Challenge. The two tribes were very evenly matched, and Kelley avenged her loss to Jaclyn in the first round by defeating her in the final round, securing immunity for Hunahpu for the second straight time.
However, Tom is the only person to win this challenge twice since Tyson only won it in his second attempt.
Both competed in a variation with water and mud.
The occurrence of this challenge in Survivor: San Juan del Sur marks the first time a challenge has ever taken place in the ocean in seasons filmed in Nicaragua.