You might be a little confused. I had to check the tags of this comic from the Awkward Yeti to know what the last guy is. He's the gallbladder, one of those abdominal organs that you really don't understand, like the spleen and the pancreas. The gallbladder stores bile and releases it into the digestive system a little at a time. It can be removed if it causes trouble. So what's he doing? Causing trouble, by producing gallstones. Nothing to be proud of at all. One gets the idea that he may feature prominently in an upcoming arc of the comic, and there's no doubt he'll cause trouble.