ibex biex iebx eibx beix ebix ibxe bixe ixbe xibe bxie xbie iexb eixb ixeb xieb exib xeib bexi ebxi bxei xbei exbi xebi
Note: these 'words' (valid or invalid) are all the permutations of the word ibex. These words are obtained by scrambling the letters in ibex.