Gravios is the mature form of Basarios. Easily one of the largest wyverns found in the series, which may intimidate the inexperienced.
Because of its weight, Gravios do not have a tendency to use flying as a method of travel like most other wyverns, instead they will walk from areas to areas, or swim through tunnels hidden under lava. Similar to Basarios, it only uses its wings to get out of trouble, like when the effect of Pitfall Trap has run out or when he has moved too far out of bounds. It can be found in the Volcano and Swamp. They are able to go in and out of lava without any damage done to them. Gravios eat rocks and minerals for their nutrients. Gravios' Japanese title (Armor Monster) refers to its incredibly hard hide.
Gravios can put its enemies to Sleep with a gas emitted from pores around its body.
The stomach can be broken twice - the first will reveal the monster's muscle layers, while the second makes the break in its stomach larger. Once this happens, the stomach will receive more damage.
In Monster Hunter Freedom Unite, the red gas that comes after the beam can be predicted, as the Gravios will emit small black smoke around its body.
When its legs receive a great deal of damage, it will roll over, dealing damage to whatever it hits. Gravios will also roll over when KO'd.
It can be determined which kind of beam it will do by the sound of its voice. When it is higher pitched, its fire beam will go side to side.
At some time in battles, Gravios may seemingly fly up. However, it should be noted that there is no wind effect as with other monsters, and it will follow up by slamming its body down on the ground, inflicting some medium damage and creating a wide area quake effect.
The fire beam can be blocked using the Guard Increase skill - however, it cannot be completely blocked even when using Guard +2 and Guard Increase simultaneously - the hunter who has blocked the strike will still take damage.
Using Flash Bombs can blind a Gravios for roughly 10-15 seconds.
HC Gravios appears more mature and all of its spikes are longer and thicker. It has the ability to spit a sweeping beam at extreme speed giving any prey or predators only a few seconds to escape if they can. The beam is so strong the Gravios itself almost falls over.
On Monster Hunter Frontier Online Gravios can be a pet.