diablo-3
I found multiple ingredients for this item:
http://us.battle.net/d3/en/artisan/blacksmith/recipe/griswolds-perfection
Now I would like to know where the plans can drop. Is there a specified boss / location for this or is it just random anywhere as most of the stuff in the game? Plans do tend to drop from specific bosses though.
Chris Rasys is right.
While some achievements are character specific, the criteria for the lore and bestiary achievements (and others) are not. This means you can complete each individual task with a separate character if need be, and you will still unlock the achievement in the end.
So in this case, your solution is simple: Start a new character (of a different class, or Hardcore, perhaps!) and play through Act I again. You should pick up the missing pieces and round out your achievement.
There are three types of items with flavor text:
Legendaries and other Uniques, "Special" items like Herding Staff components, and Easter egg items.
In your case you have an "easter egg" item similar to this:
is an easter egg reference to the Borderlands boss Nine-Toes, who drops the gun "The Clipper"
Best Answer
All Legendary equipment recipes are random, but the locations of materials can be found here.
I found mine on Manglemaw at Torment V (70).