Gotou

Gotou is an "experimental" Parasite created by Reiko. He is actually composed of several combined Parasites, whose shapeshifting ability has advanced to the point where they can switch positions, each forming a different limb as the situation requires. Gotō is the most intelligent and skilled, and is the de facto leader of the composite body. Because his head and all of his limbs are made of Parasite cells, Gotō is much faster, stronger, and more dangerous than standard Parasites, and nearly impossible to injure. Gotō is the last Parasite that Shinichi and Migi take down; Gotō actually ends up causing the temporary death of Migi, and absorbs Migi into his body for a small period of time. Shinichi is left with only one arm during this period, but manages to recover Migi and secures victory. The name "Gotō" is a pun on a word "五 Go" meaning number 5, implying he can control 5 Parasites, whereas the other Parasyte in the same body called Miki (三木 Miki lit. Three trees) can control only 3.

(Source: Wikipedia)