Lahn

The lahn evolved from a population of lahnworms that became sequential hermaphrodites, with the males looking nearly identical to their ancestors, and the females taking up a lifestyle similar to the long extinct treeworm with some notable differences. Because of its similarities with its ancestor, the lahn has replaced its ancestor in Drake Chaparral. However, the lahn failed to replace the lahnworm in Drake High Grassland due to its inability to cross Slarti Polar River, survive on the beach, or survive in wooded and polar environments. As a result, the lahnworm lives in the lands north of Slarti Polar River, while the lahn dominates all lands to the south.

The female lahn has forgone a motile lifestyle and remains planted in the ground. This allows it to survive off of photosynthesis alone. The females have lost their eyes during their metamorphosis, and their tail and cloaca protrude from the ground like a snorkel. Its feet and tongue have been modified into root-like structures so that it can remain planted into the ground. However, the tongue is the only root-like appendage capable of collecting nutrients. This tongue will continue growing throughout its lifespan, constantly searching for new nutrients and detritus to collect. Over time, the tongue will arch under the creature's body and branch into a dense network. As a result, young females can be identified by their feet-roots and tongue-root being the same length and face in the same direction, while older ones have a longer tongue-root that arches beneath the body. Females have another derivative trait, which is their bioluminescent leaves. These are used to attract males during the mating season. These leaf-lights are situated at the tips of its largest leaves, and only are lit at night during the mating season. Female lahns will store sugars inside of their leaves during the fall. When winter arrives, the females will use their stored sugar in combination with their ability to absorb heat through their leaves to survive during the winter. The leaves of the female lahn are succulent and have the texture similar to beef and have a bland, mildly sweet flavor. Females occur in high population densities, blanketing Drake Grassland, Drake Chaparral, and the southern part of Drake High Grassland in a layer of dark blue. This thick field of female lahns glows turquoise during the mating season, giving the fields they inhabit an otherworldly quality. The population distribution of female lahns in Drake Rocky however, is more sporadic, with patches occurring wherever the soil is loose enough for them to take root.

Male lahns are very similar to their ancestor, the Lahnworm, with two exceptions. Male lahns have thinner, less bushy leaves than their ancestor and have a predominately herbivorous diet. Males will roam in 'lawns' like their ancestor, searching for patches of small flora to graze on. Males will also feed on fallen leaves and other decaying plant matter. Males primarily feed on Marbleflora, Pioneeroots, Sunstalks, and Fuzzweed during the spring, summer, and fall and feed on glaalgaes, cryobowls, and supershrooms during the winter. The males use the same adaptations the females use to survive the winter. Males often find safety when travelling through fields of female lahns, as their leaves are the only visible part while travelling among the females, making them hard for predators to spot.

The life cycle of the lahn has become more complex. The lahn begins life as a male, and will continuously consume small genus group flora until it reaches maturity. The flora it selects becomes larger as the young lahn grows. This takes about one month. The male will then remain a male for about three years. Upon reaching the third year, the male will bury itself into the ground, leaving only its cloaca and leaves exposed. The male will then metamorphose into a female, which can live for 25 years if not consumed. The lahn's mating season occurs in the middle of spring. Males will select females with the brightest leaves. However, males will have a harder time determining the precise brightness of female leaves in settings where the females form sprawling grasslands. This results in the grassland populations have dimmer leaves than those in Drake Rocky. After mating with a female, the male will keep the eggs in his cloaca until they hatch. The eggs take about one month to fully develop before hatching. When this happens, the male will release the young lahns from his cloaca.