1 Womb hijacking barnacles
Saccluna tops our list of incredibly dangerous parasites. Female Sacculina finds crab and slides inside at the joints. It spreads it feeding tube throughout the host’s body. Its reproductive system emerges at the female crab’s brood pouch. If the host crab is male then the parasite simply manipulate the hormone of crab for it to behave more feminine. The male parasite then fertilizes and turns the crab into parasite factory. The crab protects the eggs in a similar fashion as a mother would protect her own offspring.
2 The mind-control bug
Toxoplasma is a brain-washing parasite and is considered one of the most deadliest parasites. This parasite infects rodents by affecting their brains and eliminating their fear of cats. The powerless victims are easily observed, caught and eaten. The bug after reproducing passes out of the cat. The bug again is eaten by the next rodent host. This is the life-cycle of the bug. However the Toxoplasma can also find their way into human bodies when they eat raw or undercooked meats. Though it rarely affects felines , strange behaviors have been observed in the humans. It is also observed that they slow down the reaction time.
3 The Vampire Fish
The tiny, eel-like candiru, Vandellia cirrhosa, lives in the Amazon and feeds on other fish by swimming into their gills and feasting on their blood. According to wary locals, it also preys on humans, entering any orifice it can find (such as the anus) and lodging itself inside using backwards-facing spines. Bloated on its blood meal, it usually dies in there and only removed by surgical process.
4 Sex change bacteria
Wolbachia is one of the world's most common parasitic microbes and these bacteria don’t like males. The bacteria are passed on to their host’s offspring in egg cells, meaning that males serve no purpose to them. he male do not serve purpose on them. They also kill the males that have been infected or they force to change their sex. They can also initiate redundancy in the males by enabling the virgin births with the females. But don’t worry – although Wolbachia have been found in humans, they can only manipulate male invertebrates such as insects and worms... so far.
5 The head-splitting fungus
Cordyceps fungi-this parasite infiltrates the ants body, it controls the behavior of the ant and eventually bursts out of the head. The infected ant is then expelled out the colony. When the fungus matures, its fruiting body blooms out of the ant's head, spreading spores on the wind to infect other ants.