Falsehead Vipers are irritable, highly venomous legged serpents which primarily live in swamps and marshes. They have brilliant, mottled scales which warn of their toxic bites, which are such a strong paralytic that most organic creatures will suffer cardiac arrest from a single bite. However, their venom is not used to kill prey, but rather to defend against predators; despite their great length, the Falsehead is a rather frail animal that relies on its agility and climbing to escape from threats. Its sharp claws and prehensile tail allow it to find purchase on any surface that is even slightly rough or soft enough for the claws to dig in, no matter how vertical it is, and it isn't uncommon to see captive adults halfway up the exterior walls of Headquarters.
Falseheads are ambush predators which drop from their high perches, typically trees, to coil around their prey. Despite their bright colors, the serpent relies on the fact that many animals—researchers included—do not think to look up when checking for predators, particularly when under tree cover. Its tail is its primary killing mechanism, coiling around large prey like a snake, and swallowing smaller prey whole. The tailtip is decorated with brightly-colored plates loosely resembling an Aceranguis or something related to it, and since the tail is over two thirds of the creature's body length, it has been known to use the false snake head to scare prey towards the Viper's claws and teeth. The false snake is also a functional rattle, making a loud, grating noise that not only scares predators away, but can be used to disorient anything that stays nearby and make it think the danger is in a different direction.