There is no word that literally means "incredible" but the words "tshwj xeeb" holds the equivalent meaning. One can say "zoo tshaj plaws" instead of "tshwj xeeb tshaj plaws" but that would mean more of saying "most special" or "the best". Also, the phrase that I translated is the more formal way of speaking and matches the style of the sample sentence that was given in Enlgish.