A taco suit is a suit in the form of a taco. Adam T. Siska of The Academy Is... has worn one due to William Beckett's (homosexual)demands in a Tai TV episode.
william beckett: "let's have sisky.. walking down the street. let's have him in a taco suit."
*ten minutes later*
sisky: "i've had it with this shit! i quit, i'm done with tai tv!"
william: "you can't do that."
sisky: "just watch me. *takes off taco suit* eat taco, you bastards. *throws taco suit at william and chiz*"