Death is the inevitable and unavoidable end of life for all living things.
While not commonly understood, the greatest cause of Death is the beginning of life itself. While the start of life varies greatly from hatching and live birth to sprouted seeds, Death is the cessation of that life. With life comes exposure to many hazards and risks that can be avoided, but ultimately all living things succumb to Death itself, the means by which is unimportant.
Ailments can be treated and the living being repaired, but this only postpones the inevitability of Death. Some have employed dark magics to delay or attempt cheat Death. Colloquially known as "undead," are devoid of life, and therefore have not cheated Death, but only partially succumbed to it.
Death is absolutely inevitable. Death comes to all beings (creatures, fauna, flora) whether Death is feared and life is carefully guarded or carelessly thrown "into the wind" by taking risks.
Creatures are subject to an almost limitless list of hosts or carriers of Death. Venomous creatures, poisonous plants, and plotting enemies are just a small few of threats to sentient creature life.
Vegetation is subject to threats from fires, floods, drought, or deforestation.
Death can be temporarily avoided or postponed through various means and is species dependent, but cannot be prevented.
Death is not contagious and is entirely species dependent.
History, written and unwritten, is riddled with stories and descriptions of death in the forms of heroic tales to the simplest tutorials on plant care.
Plants have a fear of Death. They develop and grow longer and deeper root systems to obtain the necessary nutrients and water for their survival.
Creatures fear death with many means. Weapons training, safety harnesses, eating a healthy diet all stem from basic fear of Death.