So the list of codex mobs are below. Alexander Aeolus Black has by far made the most comprehensive information sheet on codex I have seen so I will link to his google sheet. It is amazing. Take a look at it here. In reference to the different skills sets these are here:
Set 1
Aim
Anatomy
Athletics
BLP Weaponry Technology
Combat Reflexes
Dexterity
Handgun
Heavy Mele Weapons
Laser Weaponry Technology
Light Melee Weapons
Longblades
Power Fist
Rifle
Shortblades
Weapons Handling
Set 2
Clubs
Courage
Cryogenics
Diagnosis
Electrokinesis
Inflict Melee Damage
Inflict Ranged Damage
Melee Combat
Perception
Plasma Weaponry Technology
Pyrokinesis
Set 3
Alertness
Bioregenesis
Bravado
Concentration
Dodge
Evade
First Aid
Telepathy
Translocation
Vehicle Repairing
Set 4
Rank 5,15,25 Codex
Alertness
Bioregenesis
Bravado
Concentration
Dodge
Evade
First Aid
Telepathy
Translocation
Vehicle Repairing
Analysis
Animal Lore
Biology
Botany
Computer
Explosive Projectile Weaponry Technology
Heavy Weapons
Support Weapon Systems
Zoology
| Pleak | Duster Gang | Renegade Hazard Mech - Set 4 |
| Arret | Stalker Bot | Merfolken - Set 4 |
| Dire Weed | Imperium Pilot | Tide Claw - Set 4 |
| Empis Wasp | Living Storm | Jellyworm - Set 4 |
| Hackfin | Whisker Fish | Paneleon - Set 4 |
| Sky Wraith | Tree Dragon | 5P1D3R-B0t - Set 4 |
| Crystal Pede | Venataur | Zeladoth - Set 4 |
| Drill Bot | Imperium Soldier | Mang Chang - Set 4 |
| Horned Bird | Vlanwing | Zyn'Dos - Set 4 |
| Sea Wraith | Protocore | Rhino Beetle - Set 4 |
| Undersea Folken | Crystal Golem | Mecha Lupine - Set 4 |
| Scout Bot | Flesh Ripper | Fenris |
| Swamp Lurker | Skyshatter Robot | Wiles |
| Lazidol | Muckjaw | Nimet |
| Skull Bird | Skreel |