Noun; meaning a person who is racist, homophobic, or otherwise depriving themselves of an open mind due to their lack of acceptance of a difference in belief or lifestyle. Slang. Can use acronym RTF as well.
"I believe that gays have no right to be in love."
"You know what you are? You're Raging Twat Fungi. Your thoughts are infectious and smelly."
Also:
"11:45:39 PM K*****: Whatever. I get angry at homophobes, racists, and any other Raging Twat Fungi." - Actual excerpt from conversation.
*Name removed for privacy