1 â¢ Ozone (O3) is an extremely reactive gas molecule composed of three oxygen atoms. â¢ 2  Ozone forms in chemical reactions in the atmosphere when nitrogen oxides (NOx) and volatile organic compounds (VOCs), also called hydrocarbons (HC), come into contact with both sunlight and heat. â¢ Ozone (O3) is an extremely reactive gas molecule composed of three oxygen atoms. â¢ 2  Ozone forms in chemical reactions in the atmosphere when nitrogen oxides (NOx) and volatile organic compounds (VOCs), also called hydrocarbons (HC), come into contact with both sunlight and heat.
Grolar bears. The offspring of a grizzly bear and a polar bear, a grolar bear is one beast you don't want to meet in the woods. Interestingly, unlike many hybrid animals on this list, grolar bears are known to occur naturally in the wild.
Ursus arctos horribilis. Standing as tall as 2.5 m (8 ft) and weighing up to 360 kg (800 lbs.), the grizzly bear is a subspecies of brown bear that inhabits western Canada and the northwestern United States. Grizzly bears are specially adapted to survive the changing seasons.