Tumbleweed

Tumbleweeds are world objects in Fallout: New Vegas.

Characteristics
In New Vegas, tumbleweeds appear as balls of wheat-colored weeds which roll around the Mojave Desert. Often they can get stuck on things, such as the buildings of Goodsprings.

Tumble weeds travel west which could imply that there is a slight westward breeze in the Mojave Wasteland.

A tumbleweed is very light, so shooting it will make it fly several feet. Because a shotgun shoots many pellets at once, even more for the sawed-off shotgun, shooting it with one will commonly send the tumbleweed flying into the sky so far that it usually disappears from sight before it can be seen landing.

If you jump on top of one (you might need to wedge it in between some props to do this) it strangely makes the same noise as walking on a metallic platform.

Radioactive tumbleweed

 * A radioactive version of the tumbleweed exists within the resources of Fallout: New Vegas, but remains unused. Identified as Radioactive Tumbleweed, it emits radiation similar to a glowing one, is classified as a creature, consequently moves under its own power, and can be killed.

Bugs

 * Occasionally Tumbleweeds may be found frozen in place almost as if they were scenery; particularly around Novac. Just as before, jumping on top of them yields a metallic sound.