Rotten Apple
Drops from Nathanos' Chest. ok, i got the 100% drop method: 1. it does not matter whr the 7 trees are, and no need to click them all 2.
Rotten Apple is a Battle for Azeroth toy that drops from Nathanos' Chest 
inside a Horrific Vision of Stormwind after interacting with rotten apple items found near trees in the Cathedral and Canal areas.
Guide awaiting review
Locate the Apple Trees
Inside the Horrific Vision of Stormwind, head to the Cathedral and Canal areas where 5 trees with rotten apples are found. Use these locations to find them: at 57, 55, at 60, 58, at 65, 62, at 72, 67, and at 67, 51. The apples on the ground near each tree can be hard to spot.
Kick or Click the Apples
Click a rotten apple — it will either bounce around (those are spiders) or spawn maggots. Kill any maggots that appear, and bounce the spider-apples repeatedly. Find one apple you can click infinitely without it spawning maggots, then click it at least 100 times to build up the drop chance.
Walk to Alleria, Don't Mount
After clicking the apple 100 times, walk or run to Alleria — do not mount, as mounting may reset your click progress. Defeat Alleria and then loot the Nathanos' Chest to receive the Rotten Apple toy.
Tips
You can set up an Interact With Mouseover keybind in Key Bindings under the Targeting section, then hover your mouse over the apple and press that key repeatedly to count your clicks more easily.
If an apple spawns maggots when clicked, kill the maggots and find a different apple — you want one that bounces infinitely without spawning maggots for the most efficient clicking.
