[Salamander8]

Available Pretenders:
EA R'Lyeh is very limited in it's choices for pretender chasses but they can use the following:

Monolith:
I have to be honest, I've never really used this one. I've had a lot of success with immobile pretenders, but have not tried Monolith.

Wyrm:
A popular SC pretender. The Wyrm is an excellent choice for an active combat pretender. No starting magic is a drawback, but it has some nice advantages with it's regeneration, 100% poison resistance and basic fear.

Son of the Sea:
More magically inclined (water 3 default) than the Wyrm but not as good at straight up combat, the Son of the Sea can also bring land-dwellers below the sea safely.

Lich and Master Lich:
These are standard broad spectrum magic pretenders. Both start with death magic, but the Master Lich has cheaper access to other magical paths, while the Lich is more robust in battle.

Void Lurker:
One of my personal favorites for MA R'Lyeh, but less so for EA R'Lyeh. The Void Lurker has cheap access to magic paths beyond it's starting astral 3, is ethereal and has a mind blast attack. It is immobile. It is also surrounded by a poison cloud, so watch where you place him in battle. It also does not eat.

Ancient Kraken:
Another good SC Pretender. He starts with no magic but is slightly cheaper to pick magic up than the Wyrm (40 as opposed to 50). He has 100 Darkvision, 50 poison resistance, and has recuperation.

Polypal Queen:
This is my personal favorite EA R'Lyeh pretender, although much of this is from her whole concept as the mother of the entire aboleth race, I feel she is still a solid if immobile pretender chassis. With some nice abilities such as: Blind , poison resistance of 100, and she creates freespawns of Polypal Spawns when in a friendly aquatic dominion. Her magic starts at astral 1 and water 1, with new paths costing 25. She has 3 mind blasts when pressed in battle, and does not eat.

Ghost King:
A classical favorite, the Ghost King is expensive, but his high fear, combined with being ethereal and sneaky can help with reduced casualty conquest of neutrals. Extra magic path cost of 20 is a nice feature as well.

Arch Mage
He rides a trampling lobster (payback for all that seafood!) and while he starts with only water 1, buying him additional paths cost only 10 points.

Scales:
These can be (and usually are) hotly debated and everyone has certain scales they love/hate, but I will give a basic rundown.

Order/Turmoil:
I am not a fan of Turmoil as losing money and having more random events is not my cup of tea. However, if you take high Luck, turmoil can certainly give you a lot of good events. Order gives some money back and can reduce the effect of misfortune. I normally leave this neutral, or slide it to order.

Productivity/Sloth:
I again found Evilhomer's advice to be spot on and highly recommend Sloth 3 as EA R'Lyeh. In fact, I recommend it more for EA than MA or LA R'Lyeh as we don't even get the Meteorite guards that MA and LA have (decent slave troops with extra MR). Most of the units we will be using cost just 1 resource. The gold loss is only 6% at Sloth 3 and other scales can make up this loss if you wish.

Heat/Cold:
Cold does not effect the income (although it still does effect the supplies) of underwater provinces so you can take it fairly easily. I used to always hold this neutral as R'Lyeh, but taking some cold is not too terrible for your land campaign later, and has only minor effects on your water campaign.

Growth/Death:
Growth is a good scale for almost anyone. The extra income can help balance your Sloth3, the extra supplies can help with Cold/Heat, and extra growth means even more money and supplies! While our main mages are not really in any danger of old age (barring spells like Decay anyway), I cannot recommend Death as EA R'Lyeh. Growth is even more attractive and Death less attractive in a longer game. Growth of any level is good, but if you can wring out Growth 3, it is highly recommneded.

Luck/Misfortune:
I strongly advise against taking Misfortune if you also take Death, which I recommend against taking Death in the first place, if you do, do not take Death 3 and Misfortune 3 as this opens up some downright devastating events. Luck+Turmoil is interesting. I usually leave this neutral or give myself some luck.

Magic/Drain:
R'Lyeh is infused with magic so Drain is not only not thematic, it is counter-productive. Your main forces will be based on Mind Lords and Aboleths which are very heavy magic-users. A little magic can help quite a bit. It makes all your researchers more efficient, you already have many units with high MR (Aboleths and Mind Lords have 18 and 20!) so Magic's reduction of MR is not as bad for you as many others, and makes all that magic you will be throwing less exhausting. I have done well with a straight zero, but taking some is certainly not a bad idea.

Just looked at the time! I'll have to work on this more tomorrow and expand from here.