Never given an official name, Sickly Stomach is a stomach projecting a puke body. Both ends of the stomach are connected to the barf and both share the same consciousness. Dr Phage refers to the stomach as the original body, so he wasn't always looking like this. Feeding can also take place by pouring food in his puke body. His stench is overwhelming. - Wiki 

[A being of pure hunger, fitting being a stomach.]