The name “dragon” is recognizable, but the average instance of the creature is not.
The youngest version of this creature is often mistaken for an eel, though it is as much described as an amphibious saltwater snake.
As the creature grows, it comes to reproductive age fairly quickly - the only reason the species survives. It’s digestion takes a shortcut in adding body mass - organic materials are not broken down completely, meaning samples of its prey will be found in its body. As cells split, the foreign genetics are integrated rather than rejected, frequently rendering the animal sterile after a few years, before its attained a human weight.
This process slows simply because of the growing mass of the animal, but never completely stops. Bats are a surprisingly frequent victim, though quadrupled creatures are also obviously on the menu in some regions.
The “hydra” form has been argued to be a case of cannibalism.
There has been frequent speculation - and the rare unfortunate experimentation - that consumption of humans was bound to enhance the creature’s intelligence. Those who pursued this line of thought ignored the consumption mass to body mass ratio, and on top of that, the protective scull that significantly slowed digestion, and therefore left a brain as viable as that when an Pharaonic embalmer emptied one through the nasal cavity.
The lore of an intentionally separated and disguised head - acting as a scout of sorts - is not to be taken seriously. This is generally held to be due to early pack hunting tendacies and perhaps the consumption of a dolphin. The modern substiution of ‘plasma’ for 'miasma’ is a misuse of the term by pseudoscience-apealing individuals.
Hording is a confirmed tendency, though it should be considered a scaled up version of nest building. Due to their genetic aggregation, their own perception of their horde must be varied as the individual.