These herd animals can be aggressive when protecting young and during the mating season, but they generally prefer flight to fighting. A bison stands more than 6 feet tall at the shoulder and is 9 to 12 feet long. It weigh 1,800 to 2,400 pounds. A frightened herd of bison flees as a group in a random direction (but always away from the perceived source of danger). They literally run over anything of large size or smaller that gets in their way, stampeding them. A bison is found on the temperate plains, either solitary or in a herd. Some druids choose them as their animal companion.