Spiny Dwarfjack

The Spiny Dwarfjack split from its ancestor. It became very small due to island dwarfism. At its size, its ancestor’s armor wasn’t especially effective, so it has elongated the scales on its back into hedgehog-like quills. These are not as mobile as hedgehog quills, however, and as such it has a quilless belly so that it can mate. Similar to its ancestor, it is a burrower, though it has also regained some ancestral nest-constructing instincts and fortifies the burrows with bits of wood collected from small flora. It can gather these by backing into flora while swinging its sharp tail from side to side, cutting through stems and saplings with ease. It carries the materials back to its nest in its mouth or tucked between its quills. If it has too much to carry that way, it can also walk on its hind legs with additional materials gripped in curled forepaws. It will also use twigs from fallen branches, but it has a preference for fresh material because it is more flexible.

With no endothermic omnivores on Hydro Island, and no omnivores at all within its size range, the Spiny Dwarfjack has claimed a generalized niche eating various small flora and fauna. On occasion, it is known to board damaged or under-construction Seashrog nests and consume the borvermids inside. It is also able to consume iron fauna and flora, though it does not use most of the iron and as such its poop is unusually iron-rich.

The Spiny Dwarfjack, like other tamjacks, is placental. It mates belly to belly, like many spiny animals on Earth. At its very small size, its gestation period is 30–40 days long, and its babies are born naked, blind, and helpless. They are born too large to fit in a pouch, though the pouch is retained to protect the teats when not in use. They take only 2 months to mature, a significant speed increase from its ancestor. The Spiny Dwarfjack can live up to 5 years.