From Homestar Runner Wiki
Occasionally in toons, a T-shirt will make an appearance. None of these shirts were for sale in the Store when they first appeared, although they bear similar designs. Only Cool Tapes and You Reek-A have thus far become real T-shirts available for purchase in the store. They can usually be found in Easter eggs.
|Summer Short Shorts|
|Summer Short Shorts||
Smart As Peanuts
I'm With Glutton Camp
|Cool Things|| Cool Tapes|
|underlings|| You Reek-A!|
A white shirt showing a scientist with a clothespin on his nose and holding a test tube. The caption below reads "You Reek-A!". It subtly conveys to an underling that they smell. This shirt used to be available for purchase in the Store.
|The Limozeen Advantage|| Advantage|
A black shirt for the all-girl metal band Advantage. It reads "ADVANTAGE" in pink letters, and shows a pair of fishnetted legs in pink tiger-striped boots, with a yellow swash in the background.
|yes, wrestling|| Jack 'Emite In Training|
A red shirt with the text "JACK 'EMITE IN TRAINING" written on the front in white block letters. For the young male fans of the Jack 'Em Up Kid.
|yes, wrestling|| Jack 'Emette In Training|
A pink shirt with the text "JACK 'EMETTE IN TRAINING" written on the front in white block letters. For the young female fans of the Jack 'Em Up Kid.