The Gulpena is an opportunistic and ambush predator found in various parts of Thistleland. Gulpenas appear much like hyenas in form and size, however certain large physiological differences and their feeding methods set them apart.
The most immediately noticeable thing about a Gulpena that distinguishes it from a hyena is it's mouth. Large and wide, its structure resembles that of a Pelican eel and is able to open to a similar degree, allowing it to consume extremely large prey. This strange lower jaw is known to loosely flap open and closed while the Gulpena gives it's own version of a hyena laugh, a sound that has a slight echo to it from the jaw and throat shape.
Further inspection would reveal that the Gulpena has a looser underbelly and if touched the torso would seem less rigid then one would expect or an animal with a rib cage. These are results of adaptions that allow the Gulpena to rapidly consume live prey whole, the swallowing and feeding capacity for a Gulpena potentially being greater then the Gulpena's own size.
If a Gulpena consumed prey that is large enough to render it's legs useless, paws not able to reach the ground, it will rely on a less efficient method of movement to find a place to rest off it's meal. Highly flexible, they will slowly slither along the ground in a manner similar to snakes, tucking their front legs to the side and back legs behind it. This method of moment is often considered as comical as it is creepy.
While it has been shown that once eaten by a Gulpena it is beyond the powers of most animals to escape, Gulpenas are surprisingly delicate from injury on the outside. This is the downside to their adaptations, their flexibility and ability to stretch to consume rapidly making them loose many of the protective measures most mammals have to blunt trauma. It is for this reason they are ambush and opportunistic hunters.
Typically a Gulpena will wait in a secluded place, often hiding in the shadows or other well concealed position. They will wait for any animal be it large or small to pass by, often having trouble suppressing small hyena-like giggles from time to time. If the animal is alone and the location isolated enough they will make their move, rapidly moving their large jaws over the victim and swallowing it rapidly. With the still-squirming prey in their stomach, the Gulpena will either retreat to a private place to enjoy it's meal, or if the current location is isolated enough, will sprawl out where they are to sleep. Due to their flexible and loose jaws, throats and stomachs, they usually cannot prevent somewhat fresh air from reaching the victim inside.
Smaller meals up to the size of the Gulpena, up to and including people size, typically take a Gulpena two weeks or so to digest, and at least one adventurer with supplies has been rescued from a Gulpena alive and mostly unharmed after one week. Larger prey then the Gulpena take longer as one would expect, typically taking more then three weeks to digest for creatures such as Bearten. Anecdotal reports tell of Gulpena very rarely eating a weakened or injured Red Planta, though such reports are unverified. With any prey that stretch the Gulpenas stomach, it is known that light will pass through the stomach to a degree, allowing the shape of the prey within to be seen and with prey the size of a person or more sometimes even the colour of the victim may be made out on less plump, more hungry Gulpenas.
Due to their delicate nature to external attack and their hunting methods, if a person can see a Gulpena they are typically in no danger, Gulpena have been known to approach people who are not hostile, and even play chew and lap at them if allowed. This is due to the risk of a single punch from a struggling victim is not worth the Gulpena attempting to attack, and the fact that Gulpena are often curious creatures to new people. However, if someone is in a shadowy place, or an isolated position and can hear the soft, hollow sounding giggle of a Gulpena, they are advised to immediately leave the area and head to a more open space, and they are undoubtedly moments away from being swallowed whole.