Monoblos are large hard-shelled wyverns that have the ability to dig and travel underground. Monoblos were named for the strong, singular horn protruding from their head, which is held as a prize by many hunters, as are their hearts which are very rare. Monoblos are in fact, the only wyvern/monster known to have two, or more, hearts (this suggests that their cousins, the Diablos, might have many hearts as well, but nothing has ever been proven and so is deemed unlikely).
They have a brown, rock-hard texture to their shell. There is a subspecies of the Monoblos known as the White Monoblos which are generally larger in size than their sand coloured counterparts and seen as more dangerous by hunters. Ironically, whilst their ear splitting roar is the bane of hunters they are weak to Sonic Bombs when not in Rage Mode and digging through the ground. It is assumed this is because of the actual shock of the bomb rather than the sound of it (though this is unofficial as of the moment).
When in rage mode black smoke will protrude out from a Monoblos' mouth and four red stripes will appear on the shell of its face, above its horn. Monoblos have only been spotted in the Desert and Old Desert regions. While they have no breath attack their roar is considered as a lethal weapon itself. Monoblos can only be hunted in Village Elder and Nekoht Quests in Monster Hunter Freedom Unite.
In Monster Hunter Frontier 10.0,HC Monoblos was released. Its attack power and speed are increased; its digging attack is much faster; it can perform a ground-slam immediately followed by a powerful horn thrust, and finally, it can perform a tail whip whilst sliding forwards.
If not in Rage, when they dig underground, a Sonic Bomb can be used to produce an effect similar to "Pit Trapping" for around five seconds.
When a 'blos wyvern charges into a wall or ledge, their horn(s) causes them to get stuck in it, after two or three times the horn(s) will break and become an award item at the quest's end. Once its horn(s) has been broken, that individual 'blos will not get stuck in any wall or ledge again. Their tails can also be severed from the body.
When a Monoblos is ledged for the first time in the battle, it will yield a 'shiny' item. This can either be 'wyvern tears' or another item of that ilk. However it is possible that the Monoblos may drop a rare 'Monoblos heart'. How the Monoblos's heart is dropped is a mystery.
"Monoblos" means "One Horned" in Latin. "Mono" the meaning for 'one' and "blos" meaning 'horned'.
Monoblos are only fought in Village Quests in any MH game they are in (currently generations 1 & 2 only); i.e.: it is impossible to find a Quest featuring a Monoblos in the Guild Hall in any game.
In the original Monster Hunter the Monoblos was an urgent quest given near the end of the village chief's list.
Monoblos gains a new attack in High Rank quests in MHFU: it growls at the hunter like when it first spots him/her and then it charges at twice its normal speed. However, the speed of this attack doesn't increase in rage mode.
Although in Monster Hunter 3 Diablos was confirmed to be a herbivore, it is unknown whether or not Monoblos is a herbivore, carnivore, or quite possibly, omnivore. The idea of it eating plants is, however, supported by its head being shaped like that of a Styracosaurus, a herbivorous dinosaur.
Monoblos does not fall inside a pitfall trap.
The Old Desert's music theme "真紅の角 (Crimson Horn)" is made for Monoblos.
HC Monoblos returns with new looks and behaviors. Its horn appears longer and its body and tail is more spiky. Attacks include smashing the ground with its chin causing a quake then rising with its horn and a tail attack were its whole body moves were its tail is pushed twice.