This relatively weak Astromon subsists mostly on small insects and animals. It will usually run when it sees a predator, but when backed into a corner it will stand and fight. It uses venom with paralytic effects that can stop the nervous system of predators many times larger than the Wormtail.
This peculiar Astromon changes its body temperature to match its surroundings. Due to this, it exhibits decreased activity in cold areas, but in tropical areas it can sustain its normal level of activity almost indefinitely. Some researchers theorize that a Wormtail's meager diet is related to its fluctuating body temperature.
The venom a Horntail spits only paralyzes an organism's nervous system, and does not cause any fatal effects such as cell death or the coagulation of the blood. It is for this reason that researchers are actively looking into using Horntail venom as a viable way to induce anesthesia.
This Astromon loves to swim, and its free-flowing movements through water are often described as elegant.
Despite its two large eyes, this Astromon has surprisingly poor vision (and hearing, for that matter). However, its sense of smell and ability to detect heat are highly developed, and overall its senses are much more refined than those of humans.
Perfectly at home in the water, many Horntails actually do make their homes in, under, or behind waterfalls. According to an eastern legend, these Astromons' enjoy long lives, and will grow into dragons in the later stages of their lives.
Wormtails are generally thought to be unable to see objects that don't move, but this is actually untrue. Wormtails are keen hunters that can detect even small morsels of food with their heat sensors. The only organisms they have a hard time seeing are those with low body temperatures.
Some stories claim that Serpentails can call down rain from the heavens. Of course, controlling the weather would be hard for a regular Serpentail with their level of astral energy, but the legend has been around for so long, and has had enough eye-witness account that the subject has been deemed worthy of further research.
For a long time, it had been said that a Horntail's growth plateaus after a certain point, but as more research is being conducted, many new theories are being proposed. Some tribes in Orisia have carved giant glyphs of Horntails larger than one could imagine, and the recent discovery of a giant fossilized fang has completely changed the direction and paradigm of Horntail research.