Screech Screeches at "Celebrity Fit" Contestants

TMZ has obtained a wacky video clip from this season's VH1 "Celebrity Fit Club," where Dustin Diamond aka Screech goes absolutely crazy and drops a vicious rant against fellow D-list celebrity contestants.

Diamond spews slurs toward his fellow dieters, calling them "retarded" and "morons!" The former child star and porn actor then threatens each of them by saying, "I would like to slap the spit out of their mouths!" DD then targets "American Idol" castoff Kim Locke, by telling her she is a "big girl" and will always be one.

Click here to watch it unfold!