There is such a parasite, which will first plunge into the victim's body, leaving a dendritic object in the host's body, completely sucking up the nutrition of the host, and then "shooting" the offspring through the host's body. If the host is male, it will also castrate the host conveniently.

You think I'm talking about the face-hugging worm in Alien? No, let's talk about the protagonist of this answer-the crab slave.

The black line and the swollen area of crab tail in the picture are barnacle crab slaves.

Crab slave (Sacculina sp.), also known as crab parasitism, is a small creature living in the ocean. It has a soft oval cystic body, no mouthparts or appendages, only developed gonads and mantle.

Usually, it will float freely in the sea until an unlucky crab passing by meets it. The female crab slave will find the crack in the crab shell, take off her mantle and inject herself into the crab. Then the crab slave will grow whiskers like roots, and the roots will spread freely in the host body, passing through the muscles, nerves, internal organs and other tissues of the host, forming white linear branches with a diameter of about 1mm, occupying every part of the host body a little.

Crab slave squeezes the host's body fluids, frantically grabs nutrients and grows rapidly until generate comes out of the crab's body. ...

The most terrible thing is that the crab slave will not kill the crab during the parasitic process, and the host miraculously survives and can grow periodically until the host enters the breeding period.

If the host is a male crab, the crab slave will affect the balance of hormone secretion in the body, making the abdomen of the male crab flat and look like a female crab. At this time, the crab slave has invaded the brain of this unlucky male crab and turned it into a puppet of the crab slave (at this time, it can be considered that the crab "Ben" is dead, which is tantamount to walking dead). At this time, the huge ovary of the female crab slave grows slowly in the original reproductive area of the male crab. Attract male crab slaves out of water to mate with them. The male crab slave inserts his whole body (...) into the other's cystic structure, and then turns himself into a cell mass with testicular function, producing sperm to fertilize the ovary produced by the female crab slave.

Then the male and female crab slaves jointly manipulate the puppet host to provide energy for reproduction and feeding, and spray astronomical fertilized eggs to the surrounding environment until they die.

Infected crabs hang on the genitals of crab slaves.

If the host is a female crab, the step of hormone castration is omitted.

But crabs often live longer than crab slaves, so most crabs can still escape such a tragic and horrible fate, leaving only a scar full of stories in their abdomen.

But it can still be eaten when cooked.

Aren't you a little lucky that there is no parasite like "human slave"?

Of course, if you don't have a sense of substitution, you can think of the crab slave as a face-hugging bug that lights up your mind control skills. ...