Smog quest
Like most of Epic Quests, it does not matter which of your dinoz completes each action, you can use any and all of them. You will save a lot of irmas by have one dino at Grandpa's and another dino at the Mutant Falls fulfilling those parts of the dialog. Note that you can do this quest while performing other quests as well.
Before the beginning, you need a dinoz that has:
- Acces to Dark World:
Piece of Dark Orb or 
Elixir - Access to Magnetic Steppes:
Blacksylva Key - 3 dinos with
or one with Gold digger from Klutz missions (?) - 1
Sharpened Claws - Laboratory (clan intiative like Dinotown Clinic)
Frish Port, talk with the Barfly
Barfly
Frish Port (Dinoland)
Then talk with Jove Boze
(if you never went to Monster Island with the dinoz, it's the second Jove).
Go to Klutz Workshop
Klutz
Klutz' Workshop (Atlantean Islands)
At Klutz Workshop, talk to Klutz
(2nd answer on EN, 3rd on FR due to missions existence).
At the Forges, talk to Forger.
At the King Citadel, talk with the Guard.
At the Neerhel Paths, dig thrice.
(you will need 3 dinoz with shovel).
At the Forges, speak with the Forger.
At Klutz', talk to him
(you can have the choice to leave with him, or not, depends if you got dinoz at Frish already or not).
Beware: Klutz won't be at the location until you finish next steps.
At Frish, talk to Klutz, wait 2 hours. Then talk again with him.
At the Coral Mines, talk with Jove Boze
(you will open the Coral Mines Icerberg road for your whole account at this point).
On the Iceberg, event "...". Then dig to find an iceberg iceblock.
At the Forges, speak with the Forger.
At the University, speak with Professor Eugene, then speak with Professor Henderson, show him your Sharpened Claws.
Sharpened Claws.At BrutForce, speak with "..." (Omar Non), give him 1.000.
At Uni, speak with Omar Non.
On the Iceberg, speak with Professor Henderson. Let's go for 300 clan action points to build the Laboratory.
Then talk to Henderson, 6 hours waiting.
At the Laboratory, speak with Henderson.
Speak with Omar Non.
At the Pit (Dark World), talk with Gulom (3rd answer).
Inside the Dark tower, the 1st level will branch into the 2nd level and the 3rd, choose the latter and continue up to the last level. "..."
You will fight an Iron Alchemist (not a hard fight). Then wait 6 hours, then take the dark energy.
At the lab, talk with Omar, you will get a fight against a dark leech in the midst of dialog
(easy fight but around 40~70dmg).
You will face several directions, each time you choose a wrong one, a fight vs leech(es) will occur.
Choose whatever first (it seems the first choice will never be the right choice), then "turn back", then "left" and "right".
On the Iceberg, talk with Omar Non.
At the Observatory talk to sage Menthos & wait 3 hours
Smog hunt:
Beware moving around lvl 62+ dinos in dinoland and the islands; there will dark monsters.
- Coral mines: talk to ... (combat with 3 dark smog)
- Sinister Path : same (2 dark smog)
- Precipitous Hills: same
- Palace : 2 dark smog + 1 Mega smog
27. At the Laboratory, talk to the prof
Enter the labyrinth
Level 1
Level 2
Level 3
Level 4
Level 5
Level 6
Direct route:
Level 1, key then A
Level 2, key, key then C
Level 3, D
Level 4, G
Level 5, H
Level 6, key then H
Level 5, I
Level 6, J exit
Level 2
Level 3
Level 4
Level 5
Level 6
Direct route:
Level 1, key then A
Level 2, key, key then C
Level 3, D
Level 4, G
Level 5, H
Level 6, key then H
Level 5, I
Level 6, J exit
The Dark Leeches have perception and around 250hp. And are not immune to poison/petrify.
The Tenticular Leeches have perception and around 300hp. They appear to have without mercy, but are not immune to petrify.
Spaghetti give the most xp. They have around 500 hp, hit about 50 dmg to lvl 60s. They have perception but no WM and are not immune to poison/petrify.
At the bottom of the lab talk to ...
Fight the biomechanical guard (Easy Fight) and go back to the surface
Laboratory: Talk to professor Henderson and receive a 
Smog Egg and Epic reward 
Smog Trophy.
Smog Egg and Epic reward Smog Trophy.