Creeper

The Creeper (Ekrixibrya reptis) is a highly-derived seedless vascular plant which has the ability to walk. Its most characteristic feature is its explosive capabilities, which make it a subject of much fear among the peoples of the world. The plant-creature is also known for its characteristic appearance- long trunk, four short stubby legs, and its ugly 'face'. The creeper motif has become a lasting symbol in many world cultures.

Naming and Taxonomy
'Creeper' is a term in Traveler's Tongue, referring to the silent sneaking that the adult creeper makes. The scientific name, Ekrixibrya reptis, can be broken up into its genus and species names: Ekrixibrya means "explosion moss" in Old Viodoxan, as the creeper resembles some sessile mosses, and of course, explodes, and reptis means "crawling" or "creeping", similar to its Traveler's Tongue name.

The creeper is the sole known member of the order Ambulophytales, or "walking plants". Its closest living relatives are the lycophytes, also known as clubmosses. Preserved spores similar to modern creeper spores are known from amber fossils dating back 54 million years, making them a somewhat ancient lineage. It is unknown, however, when exactly these plants evolved their ability to move about.

Anatomy and Physiology
The creeper's mature form is between 1.4 and 1.8 meters tall, with four 'legs' known properly as pseudopodia. Each pseudopod contains a system of modified xylem which pump water through the pseudopodia, creating a hydraulic system not unlike the tube feet of a sea star. The black growths at the bottom of the pseudopodia are a complex of root hairs and mycorrhizae, which allow it to absorb water and nutrients while on the move.

The creeper's body contains large amounts of sulfur, which they absorb from mineral deposits. The sulfur is used to start a chemical chain reaction in an organ called the explososome. The explososome contains cilia which are synced to the creeper's walk cycle; otherwise, walking would activate the chemical reaction. Whenever an animal is within a three meter radius, the cilia are vibrated enough to initiate the reaction, quickly turning the plant's green flesh into a hot white. In 1.5 seconds the creeper goes from ambient temperature to nearly 800°C, and explodes violently onto its victim.

The creeper's face is not an actual face, but the sporangia (spore-bearing organs) of the plant. They are indented into the head of the plant, and it has been theorized that these are the basic sensory organs of the creeper. They function much like the pit organ of some snakes, seeing only heat.

Life Cycle
The adult creeper so commonly recognized is the mature diploid sporophyte of a much more complicated organism. When the creeper explodes, the spores have two potential paths. The first path is to latch onto surviving victims, where they are dispersed into the world. This is how the creeper has such a wide distribution across Rathnir, Eldham, and formerly Jagdas. The second path is much more sinister, involving the death of the explosion's victim. The dead body is metabolized by fungi and bacteria, and the nutrients released aid the spores, and later gametophyte, in growth. Like all plants, creepers undergo alteration of generations. The haploid gametophyte form of the creeper arises from spores, forming a small leafy mass called a prothallus. The creeper's prothallus is similar to that of a fern's, but grows much larger. It may even take the form of a vine-like plant, which is why many other vines are also called "creepers". The gametophyte produces gametes, which come together to create a new diploid sporophyte.

The new sporophyte grows off of the prothallus, initially resembling a typical clubmoss or a sapling. When it reaches its full height, the mature creeper develops sporangia and will slowly begin to walk around. While the sessile phase can last from 5 weeks to several months, a typical ambulatory sporophyte lasts only about three weeks.

It is speculated by some that creepers don't actually reproduce, but instead are constantly transferring themselves continuously as not to age due to their semi-asexual mode of reproduction. Due to the fact that hundreds of new creepers can theoretically arise from one successful kill, this is thought to mean that creepers function in some sort of hivemind. This also implies creepers have a higher level of understanding their situation than many realize.

Cultural Interaction
Since creepers have a wide range, almost every culture has some kind of relationship with them. They were feared things, as they can kill several people at once. Bas-reliefs on ancient Najeri temples show creeper "faces" (sporangia) on them, and creepers are a common motif on Guren bronze vessels. Due to their motile nature, they were at many times considered to be animals, almost as how sessile marine animals like sponges and corals were considered plants.

About 2800 years ago, people discovered that creepers were an excellent source of sulfur. The plants were harvested for their sulfur, and killed ritually as they were deemed too dangerous to be left alive. As such, they have become rare in recent decades to the point of being critically endangered.

Urban legend has it that if a creeper is shot with an arrow by a reanimated skeleton, it produces a vinyl record disc upon death. There is no scientific explanation nor any testing that demonstrates this to be remotely true.