星尾兽是岛上最不具进攻性的草食生物之一，主要生活在山地和草原上。星尾兽有又大又厚的硬甲，它壳下存有的脂肪可以用来在寒冷中保持温暖和提供食物。 星尾兽已经很好的适应了岛上的危险，甚至可能比甲龙还要生存的更好。 星尾兽对捕食者有两种不同的反应。对于小型对手，星尾兽会利用它布满尖刺的尾巴来造成尽可能多的伤害。 但对于大型捕食者，星尾兽会把自己的尾巴缩进自己的甲壳，从而变成一个让捕食者几乎无法穿透的坚实装甲球，并且它能以这种形态安全的“滚”走！
Common name: Doedicurus
Species: Doedicurus custosaxum
Doedicurus custosaxum is one of the Island's non-aggressive herbivores, generally found in the mountains and grasslands. Large and well-armored, it has a supply of fat under its plates to keep it warm and fed in the cold. Doedicurus has adapted well to the dangers of the Island, perhaps even better than the Ankylosaurus. Doedicurus has two very different reactions to predators. Against smaller foes, it generally uses its spiked tail to inflict as much damage as possible. Against larger predators, however, it pulls its tail underneath itself to form a solid armored ball that is nearly impossible for creatures to pierce, from which it can actually "roll" away to relative safety!
Doedicurus is a highly prized work animal on the island. Its spiked tail is ideal for quickly shattering the large rocks, so Doedicurus is a very efficient quarry worker. In addition, its affinity for rocks has allowed it to carry stone at a reduced weight. In case their quarry gets raided, Doedicurus-riders have a very difficult-to-kill mount!