That porn has been on other sites for years.
You want something terrifying, look up Rhizocephala.Then Liriopsis pygmaea.
>Once the female cyprid locates a suitable victim, it inserts a thin needle into a seam of the crab's armor, injects a tiny clump of its own cells into the host and discards the rest of its body entirely, losing more than 90% of its total mass. Now little more than a protoplasmic blob, it begins to grow throughout the crab's interior almost exactly like cancer, wrapping fungus-like tendrils around organs, muscles and even the crab's eyes.
>Soon, the intruder reveals its presence to the outside world as a bulging sac known as the externa, located where the host crab would normally carry a clump of eggs. If the host happens to be male, the parasite simply alters its hormonal balance until the crab is shaped like - and behaves like - an egg-carrying female.
>It is at this point that the male barnacle finally enters the picture: Injecting himself into the externa, he fertilizes the parasite's eggs and the crab is induced to nurture them as it would its own, carefully cleaning and protecting the bag of baby barnacles. Eventually, the crab will climb atop a rock or coral and shake its body in the water's current, the same action normally used to release crab larvae. The crab will spend the rest of its life raising the offspring of this cancerous invader again and again, unable to ever reproduce with its own kind.
>Rhizocephala may be among the world's weirdest parasites, but that only means Liriopsis pygmaea boasts some of the world's weirdest hosts. The featureless white globes we see here are highly degenerate isopods attached to the externa of a Rhizocephalan, in turn attached to its host crab. And just as the crab is castrated by its parasite, the parasite is rendered sterile by these hyperparasites.
This has been a friendly /an/ post.