Alligator gar, or Atractosteus spatula, is a species of fish with fossils tracing its existence to the  early Cretaceous Period. These  torpedo-shaped fish have not changed many of the morphological traits of  their ancestors. Unlike many other fishes, it can breathe air, which  allows them to populate areas  dangerously low in oxygen for other water-breathers. Its scales form incredibly tough layers that are nearly impenetrable; when under attack, these scales defend well against any aggressors.   Similar to the unrelated nautilus, alligator gars live long and mature late, and after which, they spawn an obscene amount of eggs depending on  the size of the female. While they  appear passive and sluggish, these  little demons are actually voracious beasts when it comes to food, just  like the animal they were named  after. Gars are primarily  piscivorous night predators,  sometimes eating water fowls and  small mammals at the surface. They  lie in wait below the surface and  wait for prey to come within reach,  and then they lunge forward and grab  their prey in a sweeping motion  before impaling the poor sap with  its teeth.