During sleep, most systems in an animal are in an anabolic state, building up the immune, nervous, skeletal, and muscular systems. Sleep in non-human animals is observed in mammals, birds, reptiles, amphibians, and fish, and, in some form, in insects and even in simpler animals such as nematodes. The internal circadian clock promotes sleep daily at night in diurnal species (such as humans) and in the day in nocturnal organisms (such as rodents).
tyrannical - characteristic of an absolute ruler or absolute rule; having absolute sovereignty; an authoritarian regime; autocratic government; despotic rulers; a dictatorial rule that lasted for the duration of the war; a tyrannical government. authoritarian, tyrannic, autocratic, despotic, dictatorial.
Definition of tyranny. Tyranny is usually thought of as cruel and oppressive, and it often is, but the original definition of the term was rule by persons who lack legitimacy, whether they be malign or benevolent. Historically, benign tyrannies have tended to be insecure, and to try to maintain their power by becoming increasingly oppressive.