Build and Runes
Dodging his rupture by turning back shortly will let you escape him easily.
Kill him early so he won’t be able to get his Feast stacks up.
Building HP will make Cho’s true damage ultimate deal less damage to you.
Let him suffer if he misses a rupture.
ChoGath has high CC but really low mobility, especially if he misses his rupture. Picking ranged champions against him and zone him from the creeps to deny his heal can be very effective.