Rotten Apple

Rotten Apple is a food item that has the same effects as Rotten Flesh, but restores. It has a 95% chance of food poisoning you, and can be used to turn Villagers into Zombie Villagers, since these are the opposite of Golden Apples. Drinking milk or waiting one minute will cure you of its affects.

Natural Generation
They are most often obtained when an apple is on the ground in item form for 5 days, or is stored anywhere but an Ender Chest. They naturally appear rarely in Strongholds, and Nether Fortresses only. Zombies, and Zombie Villagers will also drop them too, but very rarely.

Trivia

 * Rotten Apples, are like Rotten Flesh but a tiny bit less dangerous.
 * Rotten Apples can be used to breed pigs, as they will not be harmed by the effects.