A tornado is essentially a violently rotating column of air moving at speeds up to 300 miles per hour. It is also likely to contain objects it has come in contact with on the ground, though the objects are rarely intact.
At the base of a large tornado, it is not uncommon to find a debris cloud, often called a debris ball by meteorologists. In small tornadoes formed on uninhabited plains or in desert environments, the debris cloud is made up of dust and small bits of plant material. In larger tornadoes that hit forests or inhabited areas, the debris cloud can contain planks, cars, animals and other very large objects. These debris balls can be seen on radar, helping meteorologists determine that a tornado has touched down.
Tornadoes that form over oceans, lakes or rivers suck water up when they hit the surface. This is called a waterspout. Waterspouts often suck up fish, amphibians and debris as well. These objects can be carried for miles before being dropped as so-called rains of fish, frogs or other items. Tornadoes sometimes form over large forest fires as well, though the formation process is not quite the same as with other tornadoes. These deadly fire tornadoes or fire whirls, made of air and fire, have been known to trap firefighters.