Poison/ venom based class

[Compliant]

I'm looking for a class/ prestige class based around poison: immunity to, creating of, dispersal of, natural venom, etc.

Is there some class that is based around the continued intake of poison to gain immunity and slowly becoming poisonous yourself.

In the end you would be immune to all poison, have venomous attacks, toxic contact, some sort of toxic mist attacks, and maybe acid attacks.

[Fax Celestis]

Our very own Eldritch Horror in the Playground made this once: http://www.giantitp.com/forums/showsinglepost.php?p=453145&postcount=9

[Jeff the Green]

Best I can come up with is Black Dog from Dragonmarked.