Jesper the End | Shrinking potion in "vanilla" minecraft @Jespertheend2 | Uploaded 10 years ago | Updated 1 hour ago
Commands and links stuff:

Flying falling sand command:
/summon FallingSand ~ ~3.5 ~ {Time:1,DropItem:0,TileID:155,Data:1}

Freeze mobs filter:
http://www.mediafire.com/view/cqbn1h97c81q7sr/freezemobs.py

NBTEdit mod:
http://www.minecraftforum.net/topic/1558668-164forgesspsmp-in-game-nbtedit-edit-mob-spawners-attributes-in-game-updated

How to install the NBTEdit mod:
http://www.youtube.com/watch?v=Inmlatf2lpE

Haste potion detection command:
give @a 373 1 7 {display:{Name:shrinking potion},CustomPotionEffects:[{Id:3,Duration:5,Ambient:1}]}

download the Code III (a map that contains this thing):
http://www.minecraftforum.net/topic/2196598-the-code-iii-end

download a world with just this shrinking potion:
http://www.mediafire.com/download/zxwi9b183ejj8oo/shrinking%20potion.zip