In response to matt gilbert's reply:
I looked into this because (and please, NO offense meant) it sounded like an urban ledgen...or rural ledgend. I found this:
Rarely, like all other animals, rattlesnakes are deformed by either congenital birth defect or by traumatic injury. A handful of rattlesnakes of several species have been documented over the past several decades that had either badly deformed rattles or a blunt stump of a tail without a rattle. One of these was the carcass of a male Mohave green rattlesnake with a rattleless stump. This carcass has been examined, x-rayed, and analyzed to determine the cause of the deformity. Several experts who have examined the photos and x-rays agree that the deformity is most likely the result of an old injury that healed long before the snake’s death, however, due to the carcass having been repeatedly frozen and thawed prior to examination, a conclusive finding by microscopic analysis of the cell structure of the stump is not possible.
It is interesting to note that the “rattleless rattlesnake” that is an occasional subject of nature films is an actual species, Crotalus catalinensis, that is found on a single island near the tip of Baja California – Isla Santa Catalina. However, it is not truly “rattleless.” Indeed, it produces a new rattle segment each time it sheds its skin, just like other rattlesnakes. The difference is that this species has lost the characteristic shape of the segment so that the segments no longer lock together effectively, thus the older segment is lost each time a new segment is produced. So, while this animal does not accumulate a series of interlocking segments capable of making noise, it does have a single rattle segment at the end of its blunt tail. Anyone familiar with rattlesnakes would not mistake this animal for anything else. And it is only distantly related to the Mohave rattlesnakes of the arid mainland.