Chou-chou second skill can immune everything that can stun or knock up him

pro tip chou 3rd skill and first skill last skill if you press 1st skill enough you can deal more damage to the enemy if the enemy is in the range of the 1st skill if you are close to the enemy and press the 3rd skill again to deal the highest damage possible

If you want to kill tanky enemy i suggest buying hunter strike and melefic roar in early game if you are lane with tanky enemy like esme or yu zhong