The Black Diablos is a female Diablos during the mating season. The change in colour is meant to act as a warning to other monsters, as she becomes extremely aggressive during this state. This aggression translates into her combat approach, with a significant boost of speed and power becoming highly evident.
These black-shelled Diablos are treated as a subspecies, but are actually just normal female Diablos in heat. The color change is a warning to other creatures, as they tend to become extremely aggressive during mating season.
Black Diablos' attacks in 3rd are the same as the common Diablos in the same game, but it catapults itself out of the ground more often than its ordinary counterpart. In fact, it uses this move as often as the Diablos met in Tri.
Interestingly, some brown markings are visible on Black Diablos in P3rd, further supporting the information that Black Diablos is a usual member of its species with color changes due to hormones.
HC Black Diablos has a new look, new behavioral patterns and new attacks. Aesthetic changes include one horn very much larger than the other, purple tongue and meat, more spikes and vein covered wings. Attacks include a roar so loud and unusual that it can create what appears to be wind shield over its body, unusual charging behavior were it just runs at a target (instead of charging horns first) and tail attacks were it slides in the direction it smashes twice.
On Monster Hunter Frontier Online Black Diablos can be a pet. Along with eating cactus, it is known to love eating Yale Nuts found in the Gorge and rarely the Tower, along with the rare Dosubisukasu flower from the Tower.
In MH3U Black Diablos can be hunted in the Moga Woods at night.