Stud Tail
Stud tail presents itself as a brown, sappy substance at the base of a cat's tail. Sometimes is has a foul odor. It occurs in males (usually due to stress) and is nothing serious. The secretion comes from a gland located at the base of the cat's tail. To treat it, first shave the area. This will allow the skin to breathe better. Wiping the area with alcohol may cause severe pain and burning if the skin is raw. Instead, try one of the many feline shampoos made exclusively for stud tail. They work very well.

that is very interesting. He is a male, and deaf, therefore would cause a little stress for him. But shaving his tail, there is one for ya. But at least i know now its not serious. Just nasty looking. Hummmm. I will do more research on this and see if there are other options for a cure or removal

thanks shady, i think you have nailed this one!
look at this site, explains more detait, which is exactly what it is
http://www.fabcats.org/acneandstudtail.html

thanks