Not everyone's unique
Dicyemida is a strange phylum of small parasitic animals that specialise on cephalopods.
Their bodies are not very complicated, lacking most basic organ systems common in the rest of the bilateria such as a digestive or excretory system or even a brain. Individuals of the same species have exactly the same number of cells when they are adults. The larger species can grow up to 7mm long.
Juvenile Dicyemida are found on the ocean floor in temperate oceans. Adults are found inside cephalopods and are usually temperate but can sometimes be found outside temperate regions.