The Hulks of Zoretha

Hulks of Zoretha
Alignment	Chaotic Evil
Pantheon	Elder Evils
Portfolio	Destruction, terraforming
Domains	3.5E: Chaos, Evil, Destruction, Earth, Madness, Purification, Renewal
Home Plane	Zoretha
Worshippers	The insane, nihilists, Star Spawn
Favoured Weapon	Natural weapons

Partying to bring about the end of the world.

The Hulks of Zoretha are one of the original Elder Evils. Hailing from an alien civilization, the Hulks are terraformers with the goal of exterminating all sapient life on whatever planet they're on, and afterwards bearing 'Children of Zoretha' to repopulate the world and reshape it in their image. There are five Hulks in total: four female, and one male. The four female hulks are each aligned with an element, but not the classical four; the females are aligned with Cold, Acid, Fire, and Lightning. The male hulk is entirely black, and unlike the others he has wings. Each individual Hulk is a CR 16 threat- while this may not seem like much, keep in mind that you're probably going to be facing all five of them at once.

For all of recorded history, the Hulks have been asleep and generally glorified statues, though why they fell asleep upon arrival instead of just doing what they came to do is unexplained. They are indestructible in this state, but can do nothing until the ritual to wake them up is completed. As the Hulks get closer to awakening, the moon turns red and begins to induce madness, randomly turning people (potentially including party members) berserk until the problem is dealt with.

Worship

Thankfully, most people have the sense to realize that worshipping the Hulks is a Very Bad Idea. Unfortunately, there exists a text called the Scrolls of Zoretha that can open a link between its readers and the Hulks, almost certainly driving them to insanity and Hulk-worship. These people have accrued together enough desperate and/or short-sighted followers to create a cult in service to the Hulks. At the beginning of the campaign, it's led by Janwulf Soulbiter, a Frost Giant who really doesn't care for the 'end the world' business but does like having fanatical minions to raid places with. Later in the campaign, he is replaced by Soelma, a nihilistic elf who does intend to wake up the Hulks.

There's also the off chance a Star Spawn knows of or ever serves the Hulks since apparently that alien species responsible for the Hulks also had relations with the Far Plane. Theoretically, the Hulks could also count as a Warlock patron (specifically the Great Old One type, though its more Great Old Ones here), though a DM planning on utilizing the Hulks in their campaign can, should, and will prevent this due to inevitable party conflict.