wolfs owlfs wlofs lwofs olwfs lowfs wofls owfls wfols fwols ofwls fowls wlfos lwfos wflos fwlos lfwos flwos olfws lofws oflws folws lfows flows wolsf owlsf wlosf lwosf olwsf lowsf woslf owslf wsolf swolf oswlf sowlf wlsof lwsof wslof swlof lswof slwof olswf loswf oslwf solwf lsowf slowf wofsl owfsl wfosl fwosl ofwsl fowsl wosfl owsfl wsofl swofl oswfl sowfl wfsol fwsol wsfol swfol fswol sfwol ofswl foswl osfwl sofwl fsowl sfowl wlfso lwfso wflso fwlso lfwso flwso wlsfo lwsfo wslfo swlfo lswfo slwfo wfslo fwslo wsflo swflo fswlo sfwlo lfswo flswo lsfwo slfwo fslwo sflwo olfsw lofsw oflsw folsw lfosw flosw olsfw losfw oslfw solfw lsofw slofw ofslw foslw osflw soflw fsolw sfolw lfsow flsow lsfow slfow fslow sflow
Note: these 'words' (valid or invalid) are all the permutations of the word wolfs. These words are obtained by scrambling the letters in wolfs.