Cannibal Run is a mission of the Hammerhead Shark in Hungry Shark Evolution. To complete this mission, you must eat 20 enemy or evil sharks in a gameplay session using the Hammerhead Shark. The reward for this is 375 coins.
A way to complete this mission is to go to Skull island (on the upper left of the map) because its close to the hammerheads spawnpoint and there are a lot of Enemy hammerheads spawning there. its a good start for the mission. after that you can go to the left of the spawnpoint since there are a lot of Hammerheads and Reef sharks spawning there.
Note: going to skull island can be an dangerous decision as this is one of the most dangerous locations in Hungry Shark Evolution.