Estronii

The Estronii are an ancient species that date back to the Dark Times.

Biology
The Estronii are made of durable rock, an element found nowhere else in the Universe. This makes them virtually indestructible, being resistant to bullets and lasers. They are humanoid, but very bulky and overshadow most species in height. They are also covered in spikes, and their armour is a part of their skin.

Each Estronii has a crest, which is used to send signals to other Estronii and to support their large brains. Even their organs are made of rock. They are also a very longlived species, for one individual could live over a few millennia. They are very agile, and naturally extremely strong. Females are slightly more slender than the males, but are equally as strong. Estronii lay eggs of stone, and the young have to use their spikes and strength to break the tough shell.

History
The Estronii evolved from sentient rocks, found nowhere else. They have lived since the dawn of time.