Evoglobins are an evolved species of Emoglobin who inhabit the Rump Command inside Bowser's body. In the game, Mario & Luigi: Bowser's Inside Story, they are purple and have long extendable, ribbon-like arms and legs. When Mario and Luigi explore there after Bowser has been knocked unconscious by his castle, the Evoglobins plead with the plumbers to go through the area on the Boats of Revival and revive Bowser, telling that they are a part of Bowser's soul. They are larger than normal Emoglobins; however, Mario or Luigi do not need to jump from underneath them to activate their message.
If Bowser is not in peril and the Mario Bros. decide to visit the Rump Command anyway, they will appear as regular Emoglobins colored purple, and will be silent, even if the plumbers hit them.
The name Evoglobin is a pun on the words "Emoglobin" and "Evolution".