Clams?

[lch]

Clams used to require only W2, so only only knowledge of one magic path and just 10 water gems, which could be further reduced by forge bonus equipment. Most of guides from Dom2 you'll find will mention that you should forge them whenever possible - they were the primary gem generator, much better than gem generating globals. Now they take W3N1, so two separate paths which makes it harder to forge and double the gems.

[Aleph]

W3N1 also gets contact naiad, who are able to clam spam further.

I had the best luck clam spamming as LA R'lyeh... IIRC the right slave mage random picks will be able to bootstrap to contact naiad, and it's exceptionally useful to have a massive astral income when playing the Dreamlands. There's tons of nature and water sites underwater to fund clam spam, and given what an incredible pain it is to go after Dreamlands in the water, they can usually hold out long enough for the strategy to pay off. Once that's accomplished, it's really only a matter of time until the world is gibbering, squamous, and non-euclidean.

But then again, I always say that.