Not sure if this one has been pointed out or not:
In the episode "The terrance & phillip movie trailer" when russel crowe first gets to Brooklyn New York you'll see a black kyle with a blue hat on instead of his green one in the background.

Also, although this is in season 10 in "Hell on Earth 2006" at satin's sweet 16 party when satin is talking about what he learned, you'll see a fat white guy in the background with chef's attire. Only thing different is that it doesn't say chef on his appron.

Flight 96 wrote :
Also, although this is in season 10 in "Hell on Earth 2006" at satin's sweet 16 party when satin is talking about what he learned, you'll see a fat white guy in the background with chef's attire. Only thing different is that it doesn't say chef on his appron.
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This is most likely because it's a costume party, and with many people dressed up as celebrities, somebody dressed up as Chef. He is, after all, a celebrity

I think i remember that one, and the other one on satans birthday was just a guy in costume im sure.

This.

So? Kyle was in South Park. And the only kid I saw was standing behind a disabled pickup, and you could see him through the windows. I couldn't make out a hat on him.