Oblivious Breoro is a little bit North of Acher Guard Post mixed in with the other huntable Ferrin.  What you need to look for is a white pulsing glow on the ground.  The first time you touch the glow it will give you a message and despawn.  Another glow will spawn that you need to look for nearby.  Keep on finding the glows until Oblivious Breoro spawns.  You might want to clear out some of the Ferrins as they will aggro and join in.

Parched Poison Net Scorpion is NE of Ibellab Oasis, you can find it by looking for a puff of sand that expands.  I just ran over that area and it eventually popped out of the sand.  Also note that more than one of them can spawn in that area.  When I went there, there were 2 Parched poison net scorpions there.

So I got all of the messages up to the point that is said "the Ferricas are trembling in panic as a powerful Ferrica appears"....except it never spawned anywhere.  I ran around forever and never found it.  This happened twice hours apart on two different channels.  Nothing.

EDIT: Alright, I finally have the emotes happen a 3rd time on another channel up by the elephants and after about a minute a white ferrica spawned inside of one of the large elephants and ran at me.  Holy crap, this one was annoying.

I have  amity with all those in Behr, master hunter, cook, gatherer, blah blah  and have done all quests there,  so I cannot be accurate on what you need to get the rare hunting animal information.

My first rare quest started with Material Vender Indri in Behr-the crystal alligator.

I simply checked quests with her and saw the information in three steps of where crystal alligators were.

Crystal Alligator is by the Shady Tree Forest node. Go down to the river banks and find the regular crystal alligators. I killed those alligators, and the Moonlight Crystal Aligator appeared shortly after that on the river bank on the south.

After i hunted the moonlight crystal alligator, in my knowledge list (press H) Ecology> Rare Hunting Guide was added, and  the clues for where other beasts were are found by going over the ????????. I list the ones I haven't hunted yet.

I went to all the npcs described in Behr to get the information.

Find the boy who is said to be the only one in Behr who saw the witch

Visit two brothers handling fish in Behr

Listen to those eating potato soup in Behr.

Oblivious Breoro-always get extra pay while hunting. I took the daily hunting quest from the blacksmith Jasmine of Archer Guard Post to hunt the Ferrina/Ferrica.  i hunted Ferricia/Ferrica, fufilled the quest, hunted a few more and got the message and glow. I moved to the glow, message, another glow, message and like stated the Oblivious spawned after a bit of time- I was busy shooting the panther and ferrica that came to talk to me while i was waiting.

Thats it from me so far.

I found the Parched Poision Net Desert Scorpion, thank you for the NE direction from oasis. Location visual map for me at least.

I saw a black cloud appear several times in the sand, took shots at it, then ran fast to get to it. The little black cloud moved, disappeared a couple of times and reappeared-a short distance, then when i ran over it finally-the scorpion appeared. 

Don't know if the scorpion is like many other things in the desert, but i hunted it at night, when other things seem to rez most of the time.

Just some extra information i forgot to list in.

The amount of knowledge/clues for location of the rare hunting. 

You must be at least an apprentice hunter.  When you are skilled or professional hunter there are 3 clues of the information from the npcs you talk to.

For the Rainbow fox, to talk to the fish guys, you need at least one everlasting herb and one cold draft beer (thats blue grade beer ) in your inventory to give them for location/clues. 

When you talk to General Goods vender Jensen. He will tell you about the levels of information then about Cursed Stone Cobra.

I have everyone's location, but I am missing the loveling-Star lama </3