On the inside, Durontus appears to have a complete set of working organs, though no traces of food have been found in his stomach. It it surmised that the creature creates his own energy source through the corrosive chemical "naturally" created by his body. This chemical sustains the monster, and fuels its massive body. Durontus creates so much of the chemical in fact, that his body has developed an organ to contain the excess material. The contents of this pressurized organ can be disgourged through the mouth, releasing a cloud of highly corrosive gas. Durontus' enormous lungs aid in this process as well, helping push the remaining amount outword. It should also be noted that the tremendous lung size may have something to do with his ability to breathe both aquatically and terrestrially.

Perhaps the most striking feature of the monster is his blue-grey sail. At one point in time, Durontus' ancestors may have used the sail to regulate body tempurature and energy, thought Durontus has not shown such an ability. It is wise to note, however that should his mood suddenly change, his sail will shudder violently when he becomes angry. The sail will sag when relaxed or "sad" and become nearly parallel when shocked or on edge.