Candiru

The only aspect of the Candiru's description that isn't terrifying is the fact that it's only an inch long. It is a parasite fish from the catfish family that survives mostly by sucking the blood of other marine and terrestrial animals. The majority of the time, it may be discovered in the gill cavities of different fish, but if you're not careful, it can very readily enter the human body.

Through the urethra, where it lodges itself using its spines and begins eating, this species has been known to infest swimmers. Since the candiru can remain inside a host for a long time, getting rid of it gets harder and harder over time. A candiru infection could result in severe inflammation, bleeding, and even death if treated improperly.

Kingdom: Animalia
Phylum: Chordata
Class: Actinopterygii
Order: Siluriformes
Family: Trichomycteridae
Genus: Vandellia
Species: V. cirrhosa