A shit that looks like a long, thick, brown thing that looks like a weasel

Someone who kisses up to People in hopes of getting special treatment is referred to as a shit weasel. Literally, a shit weasel rims with such enthusiasm that, well lets just say some things are best not said... Basically calling someone a shit weasel is like calling them an ass kisser, brown noser, etcetera, but moreso.

when a person gets super fucking stoned and they become a Shit Weed and they become a dick or asshole being a shit weed

When you chug a bunch of laxatives to quickly lose weight.

It is used when a person online or in-person says something stupid and/or idiotic and creates a chain of people hating on the original commenter for their terrible comment. Most of the times the original commenter deletes their comment due to the hate. (Shit-well refers to a 'water-well' (the comments) getting infested with shit comments.

Taking a bad situation and making something good out of it

I'm not quite sure of it's origin but the first time I heard it was on active duty with the US Air Force some time in the late 1970s.
A shit whistle is the item used by people, known as shit-whistlers, who tells a complicated and evolving tale that they alone believe. In psychiatry the closest term is a confabulation.