Middle-earth™: Shadow of Mordor™

There are 10 challenges. You can pick up plants anytime, even during mission, and they restore your health.
You may have to continue on your main quest to unlock others challenges. So I suggest to finish those challenge until you can't continue, to gain "free xp" to level up some perks.

Tip - Before you go hunt some plants

• If you find one type of plants near a tower, you can pick it up > fast travel to the tower nearby > go pick the plant again, to speed up the challenges.
• For the Blue "tripod", you can found one at the South of Udûn Foothills
• It can be tedious to open map just to remember wich color you have to pick to there it is :

CHALLENGE 1	CHALLENGE 2	CHALLENGE 3	CHALLENGE 4	CHALLENGE 5
2 x	3 x 1 x	2 x 2 x	2 x 2 x 1 x	4 x 2 x

CHALLENGE 6	CHALLENGE 7	CHALLENGE 8	CHALLENGE 9	CHALLENGE 10
3 x 3 x	2 x 4 x	2 x 3 x 2 x	7 x	3 x 2 x 2 x

• Here's each tower with plant location that you can see when you spawn :

Udûn

Nurn

I scoured a lot of guides online to find what I thought would be the easiest to replicate. The guide I liked most (and that got me the achievement) was this one:

The Hunt is My Mistress Guide - Shadow of Mordor by LetsPlay Community

Not mentioned in this video is the ability to easily save scum. Your save is located here:

C:\Program Files (x86)\Steam\userdata[your ID]\241930\remote\gamedata.sav

Everytime you kill a captain or warchief, your game auto saves. Backup your save when you feel it's necessary; in my run, this was crucial.

Basically, the steps are:

-Collect intel on all 20 captains by grabbing regular uruks with Ctrl, then hitting Spacebar to gather intel. I recommend saving after this. You should be maybe 7-8 minutes in at this point. Try and kill some caragors and caragaths at this point too; this will come in handy later on.
-Collect intel via a worm on one warchief; make sure it's Ukuaguga. If not, reload a backed up save OR restart if you want. The position of the unknown warchiefs is the same when you reload your save, so just choose a different one this time instead.
-Get a graug. There's a map online that you can find on Google Images for graug bait locations if you need it. Using the Sauron's Army menu, search for the closest captains (ignore those in power struggles for now) and mark them as your target. Once you find them (hit V to search in game then X to tag) eat them with the graug for a 1 hit kill. Keep in mind you actually need 10 monster kills for the objective; this will be easy to hit as most captains we will kill with the graug anyways since it's the fastest.
-Once you've killed maybe around 15 or so captains (any located in the far northeast stronghold on the map can't be reached via graug, easy enough to kill anyways though), backup your save, then go fight Ukaguga (you should be at around 22-25 minutes at this point; you'll need to lure him out) and get him low on health (be careful with finishers) until an in game "cutscene" happens where you can either kill or dominate him. Dominate him, command him to start a riot against another warchief (no intel needed to do this on unknown warchiefs), then go to the riot objective marked on your map. At this point, you should be somewhere under 30 minutes to have a fair shot.
-Finish off all of the riots, and be hasty about it. After killing another warchief, command another riot, then press K to kill all of the branded enemies for points. The warchief Zugor can be killed with ranged attacks, so kill him basically instantly with these once you face him. Ideally you'll be under 35 minutes at this point.
-Riot against the captains you still have left. Sometimes, it might be quicker not to do these via riot, such as if there's an ambush or beast hunt you can go to instead. Just kill off each of the last captains; I was a bit close on time which was worrisome but I still got it done.
-Once you kill the 20th captain, make sure you're somewhere near 11,000 points. Then, press K to kill all of your branded uruks and Ukaguga to finish off the test of the wild.

With save scum, you should be able to finish this in under 40 in game minutes. Remember, the timer pauses during cutscenes and while on the menu. It personally took me 2.5 hours of working on a single run, with lots of retrying in between. It's very very doable with the right mindset, time, and strategy.

There is 10 Hunting Challenges you can do between missions :

1... 3 Spiders

Pretty common to find, use your bow and Wraith vision to find and shoot them easily.
You can find some directly after you unlock your first Forge tower.

2... 5 Flying creatures

Same as above, use your bow and Wraith vision to slow time to find and shoot them easily.

3... 3 Caragors

They appears after the main quest An interested party is completed.
They can be either be found wandering around or in cages. Simply shoot them once or twice in the head to kill them easily;

4... 4 Rats

You can find them around any Stronghold area. Use your Wraith vision to find them.

Thrill of the Hunt should unlocked

5... 8 Ghuls

Ghuls make their appearance during the quest Shattered Memories, so this challenge will be complete in no times.
But if you don't have to do this challenge during this quest, you can find Ghuls at night or in caves.
You can also look at your minimap to seek little red marks, like Caragors one but smaller.

6... 3 Bats

They can be found in entrance of caves. Be sure to have enough concentration to slow time and snipe them, because they will fly away when you approach them.
I found bats when I left the North-West Cave of the second map, in Nurn, in direction of the stronghold

7... 1 Graug

During the mission Hunting Partners, you will have to kill a Graug.
Or you can found them by roaming or in small caves. You will see a special healthbar over them from far away.
It can be tough to kill one, but if you have the ability Shadow Mount it becomes easier, and if you have the abilty Dispatch it becomes more easier. You will just have to Shadow mount the Graug, dismount it and "dispatch" it to kill it.

8... 1 Dire Caragor

After Hunting Partners, they should begin to appear. They are white Caragors.
Like Graug, they have a special health bar so you will recognise one pretty easily. So roam around Nurn (second map) until you find one.
When you complete the mission The Great White Graug, you will end the quest on a back of one Dire Caragor.

9... 1 Ghul Matron

You can found one Ghul Matron during the Urfael Sword Mission : Nameless things or the main quest The Messenger , so if you didn't already complete that mission, go for it.
If you already did those missions, you can still lure some on the map. First, you need to travel by night until you found some Ghuls. Then, kill some ghuls until some run away. Let them run and wait for another wave. Repeat until a Matron spawn and voila !

10... 1 Horned Graug

You will fight one during the mission The Great White Graug. Otherwise, they will spawn on map after that mission.
If you already did that mission, I recommend you to have the abilities Shadow Mount and Dispatch unlock to quickly kill one.
They can spawn in caves like the one at the West of Nurn or around the first Forge tower you unlock in Udun
If there is no Graug, quick travel to a tower and go back.

Master of the Wilds should unlocked