The sword-billed penguin (Neocrossvallia darwini) is a species of primitive penguin that is native to much of the southern and southwestern coastlines of Novolaurasia on Liera. The sword-billed penguin is closely related to, but not directly descended from the long-extinct Crossvallia that was harvested from Earth to Liera during the late Paleocene, having already adapted to the warm coastal areas of the continent, they have changed very little from their ancestors.
The sword-billed penguin is a very large penguin, reaching the height of about 160 centimeters (5.2 feet) tall and weighing around 70–80 kilograms (154-176 lbs) on average, with a few exceptional specimens growing slightly larger. The adult sword-billed penguin's flippers are black; the inner sides of the flippers are white. The face is white extending far behind the eyes, which are yellowish brown; the chin and throat are white, as well, while the very long bill (which the species is named for) is pink with a black tip. The strong legs and the webbed feet are pink. Its short, stumpy legs give it a distinct waddle when it walks. The sword-billed penguin's black back and white underside provide camouflage in the form of countershading when viewed from above or below, helping to avoid detection by its predators.
Compared with more derived penguin species, the feet of the sword-billed penguin have a greater role in swimming than those of other penguins, and this species isn't adapted to standing fully upright for prolonged periods. The sword-billed penguin is one of, if not the most aggressive living penguins of Liera, being known to attack rivals and potential threats with their sharp beaks, often causing major injuries and, rarely, deaths among Lieran people through impaling their internal organs with the penguin's beaks. The sword-billed penguins forage in the open sea, where they feed on pelagic fish (such as small whalefish species) and marine invertebrates (such as squids and small crustaceans, primarily krills and shrimps). Sword-billed penguins normally swim within 20 km (12 mi) of the shore. A sword-billed penguin may consume up to 2.37 kilograms (5.22 lbs) of prey every day, but this may increase to over 3.15 kg (6.94 lbs) when raising older chicks. When foraging, sword-billed penguins carry out dives that reach an average depth of 40 meters (131 feet) and last for 97 seconds, although a maximum depth of 170 meters (557 feet) and duration of 339 seconds has been recorded.
The sword-billed penguin is monogamous; it breeds in colonies and pairs return to the same site each year. It has an extended breeding season, with nesting usually peaking from March to May in southern Novolaurasia and April to June in southwestern Novolaurasia. A clutch of two eggs are laid either in burrows burrowed in guano or nests in the sand under boulders or bushes. Incubation is undertaken equally by both parents for around 55 days. At least one parent guards the chicks for about 1.5 months, whereafter the chicks join a crèche with other chicks and both parents spend most of the day foraging in the sea. Chicks fledge at 90 to 160 days, the timing depending on environmental factors such as the quality and availability of food. The fledged chicks then go to sea on their own, where they spend the next one to more than two years. They then return to their natal colony to moult into adult plumage. When sword-billed penguins moult, they are unable to forage in the sea as their new feathers are not yet waterproof; therefore, they fast over the entire moulting period. Sword-billed penguins typically take around four weeks to molt and lose about half of their body weight by burning up their fat reserves in the process. The average lifespan of an sword-billed penguin is 20 to around 30 years in the wild and up to 45 in captivity.
The sword-billed penguin is listed on CITES Appendix I, which means that all international commercial trade in sword-billed penguins or their body parts is prohibited. It is listed as Near Threatened on the IUCN Red List since 1980, as the sword-billed penguin is thought to have declined as much as 25-30%, as a result of habitat loss and persecution, being hunted after being blamed for attacks on Lieran people children, as a result of the species' aggression. The sword-billed penguin is protected by the conservation laws and there are efforts to minimize persecution and habitat loss. Captive breeding programs may be beneficial for the species' survival.