Amphipteres grow into their powers as they age, as most companions do. Theirs is an ancient magic, and one they know how to control perfectly, even from birth. When first born, amphipteres are dependent on their human companions for food, and sleep much of the time. They are eventually able to find their own gravel and sand to consume, and are as energetic as any other youngling. In time they grow to be as large as the gryphons, though they never reach the heights of most dragons. When they are fully grown they no longer reside at The Keep, but leave to find or create their own lairs. These caves completely surround the castle but go unnoticed because they are underground. It can take an amphiptere as long as a year to make their home, as they do so by eating the rock. It would be easier for them to command the rocks to move, but for some reason this is a long standing tradition. Some of these caves even reach to the edge of the forest, or are under a field used for farming. The villagers do not mind, for the amphipteres do not bother them or make farming difficult. Indeed, despite their frightening appearances, amphipteres are happy to help those who ask politely. The towns around The Keep have several buildings formed from rock. The Keep is always being expanded, and amphipteres are more than happy to help with that work. Amphipteres do not have much need of organization, though, so the castle is somewhat like a labyrinth, twisting and turning in all directions, much like their caves.
Amphipteres are strange creatures, even compared to some of the other companions in the castle. These beautiful animals are formed from living rock, and have neither blood nor flesh to weaken them. If an amphithere is ever defeated, it does not perish, but crumbles into sand. The amphithere's body will reform from the sand, and the creature will be as it was before. It is only when they are old that amphipteres finally succumb to death, freezing in place and never moving again. Like most companions, their lives are long and full of adventures: they live for many centuries. They are happiest when roaming the world at the side of a magi, discovering new places and lost treasures. Amphipteres are most able companions, as their presence usually wards off any dangers. These animals do not have many weaknesses, though water causes them to move sluggishly and drains their powers. Amphipteres possess an old magic: the ability to control the earth with their voices. A loud roar from an amphiptere may cause avalanches or even crack the earth in two. This is very draining for the creature, though, and they must rest to recuperate. Amphipteres prefer to use small magics which can be equally devastating. One well known trick of theirs is that they can liquefy the earth, and suck their enemy downwards. Depending on their anger, the amphiptere may even solidify the earth again, trapping their foe forever. This is a rare occurrence, as it is more common for amphipteres to use their magic to aid their friends. A cry from one of them and the earth will respond, a rock surging upwards from the soil. Amphipteres can command these rocks to take any form, to be any shape. They are even rumored to have helped form the keep centuries ago.