happen ahppen hpapen phapen aphpen pahpen happen ahppen hpapen phapen aphpen pahpen hppaen phpaen hppaen phpaen pphaen pphaen apphen paphen apphen paphen ppahen ppahen hapepn ahpepn hpaepn phaepn aphepn pahepn haeppn aheppn heappn ehappn aehppn eahppn hpeapn pheapn hepapn ehpapn pehapn ephapn apehpn paehpn aephpn eaphpn peahpn epahpn hapepn ahpepn hpaepn phaepn aphepn pahepn haeppn aheppn heappn ehappn aehppn eahppn hpeapn pheapn hepapn ehpapn pehapn ephapn apehpn paehpn aephpn eaphpn peahpn epahpn hppean phpean hppean phpean pphean pphean hpepan phepan heppan ehppan pehpan ephpan hpepan phepan heppan ehppan pehpan ephpan ppehan ppehan pephan epphan pephan epphan appehn papehn appehn papehn ppaehn ppaehn apephn paephn aepphn eapphn peaphn epaphn apephn paephn aepphn eapphn peaphn epaphn ppeahn ppeahn pepahn eppahn pepahn eppahn happne ahppne hpapne phapne aphpne pahpne happne ahppne hpapne phapne aphpne pahpne hppane phpane hppane phpane pphane pphane apphne paphne apphne paphne ppahne ppahne hapnpe ahpnpe hpanpe phanpe aphnpe pahnpe hanppe ahnppe hnappe nhappe anhppe nahppe hpnape phnape hnpape nhpape pnhape nphape apnhpe panhpe anphpe naphpe pnahpe npahpe hapnpe ahpnpe hpanpe phanpe aphnpe pahnpe hanppe ahnppe hnappe nhappe anhppe nahppe hpnape phnape hnpape nhpape pnhape nphape apnhpe panhpe anphpe naphpe pnahpe npahpe hppnae phpnae hppnae phpnae pphnae pphnae hpnpae phnpae hnppae nhppae pnhpae nphpae hpnpae phnpae hnppae nhppae pnhpae nphpae ppnhae ppnhae pnphae npphae pnphae npphae appnhe papnhe appnhe papnhe ppanhe ppanhe apnphe panphe anpphe napphe pnaphe npaphe apnphe panphe anpphe napphe pnaphe npaphe ppnahe ppnahe pnpahe nppahe pnpahe nppahe hapenp ahpenp hpaenp phaenp aphenp pahenp haepnp ahepnp heapnp ehapnp aehpnp eahpnp hpeanp pheanp hepanp ehpanp pehanp ephanp apehnp paehnp aephnp eaphnp peahnp epahnp hapnep ahpnep hpanep phanep aphnep pahnep hanpep ahnpep hnapep nhapep anhpep nahpep hpnaep phnaep hnpaep nhpaep pnhaep nphaep apnhep panhep anphep naphep pnahep npahep haenpp ahenpp heanpp ehanpp aehnpp eahnpp hanepp ahnepp hnaepp nhaepp anhepp nahepp henapp ehnapp hneapp nheapp enhapp nehapp aenhpp eanhpp anehpp naehpp enahpp neahpp hpenap phenap hepnap ehpnap pehnap ephnap hpneap phneap hnpeap nhpeap pnheap npheap henpap ehnpap hnepap nhepap enhpap nehpap penhap epnhap pnehap npehap enphap nephap apenhp paenhp aepnhp eapnhp peanhp epanhp apnehp panehp anpehp napehp pnaehp npaehp aenphp eanphp anephp naephp enaphp neaphp penahp epnahp pneahp npeahp enpahp nepahp hapenp ahpenp hpaenp phaenp aphenp pahenp haepnp ahepnp heapnp ehapnp aehpnp eahpnp hpeanp pheanp hepanp ehpanp pehanp ephanp apehnp paehnp aephnp eaphnp peahnp epahnp hapnep ahpnep hpanep phanep aphnep pahnep hanpep ahnpep hnapep nhapep anhpep nahpep hpnaep phnaep hnpaep nhpaep pnhaep nphaep apnhep panhep anphep naphep pnahep npahep haenpp ahenpp heanpp ehanpp aehnpp eahnpp hanepp ahnepp hnaepp nhaepp anhepp nahepp henapp ehnapp hneapp nheapp enhapp nehapp aenhpp eanhpp anehpp naehpp enahpp neahpp hpenap phenap hepnap ehpnap pehnap ephnap hpneap phneap hnpeap nhpeap pnheap npheap henpap ehnpap hnepap nhepap enhpap nehpap penhap epnhap pnehap npehap enphap nephap apenhp paenhp aepnhp eapnhp peanhp epanhp apnehp panehp anpehp napehp pnaehp npaehp aenphp eanphp anephp naephp enaphp neaphp penahp epnahp pneahp npeahp enpahp nepahp hppena phpena hppena phpena pphena pphena hpepna phepna heppna ehppna pehpna ephpna hpepna phepna heppna ehppna pehpna ephpna ppehna ppehna pephna epphna pephna epphna hppnea phpnea hppnea phpnea pphnea pphnea hpnpea phnpea hnppea nhppea pnhpea nphpea hpnpea phnpea hnppea nhppea pnhpea nphpea ppnhea ppnhea pnphea npphea pnphea npphea hpenpa phenpa hepnpa ehpnpa pehnpa ephnpa hpnepa phnepa hnpepa nhpepa pnhepa nphepa henppa ehnppa hneppa nheppa enhppa nehppa penhpa epnhpa pnehpa npehpa enphpa nephpa hpenpa phenpa hepnpa ehpnpa pehnpa ephnpa hpnepa phnepa hnpepa nhpepa pnhepa nphepa henppa ehnppa hneppa nheppa enhppa nehppa penhpa epnhpa pnehpa npehpa enphpa nephpa ppenha ppenha pepnha eppnha pepnha eppnha ppneha ppneha pnpeha nppeha pnpeha nppeha penpha epnpha pnepha npepha enppha neppha penpha epnpha pnepha npepha enppha neppha appenh papenh appenh papenh ppaenh ppaenh apepnh paepnh aeppnh eappnh peapnh epapnh apepnh paepnh aeppnh eappnh peapnh epapnh ppeanh ppeanh pepanh eppanh pepanh eppanh appneh papneh appneh papneh ppaneh ppaneh apnpeh panpeh anppeh nappeh pnapeh npapeh apnpeh panpeh anppeh nappeh pnapeh npapeh ppnaeh ppnaeh pnpaeh nppaeh pnpaeh nppaeh apenph paenph aepnph eapnph peanph epanph apneph paneph anpeph napeph pnaeph npaeph aenpph eanpph anepph naepph enapph neapph penaph epnaph pneaph npeaph enpaph nepaph apenph paenph aepnph eapnph peanph epanph apneph paneph anpeph napeph pnaeph npaeph aenpph eanpph anepph naepph enapph neapph penaph epnaph pneaph npeaph enpaph nepaph ppenah ppenah pepnah eppnah pepnah eppnah ppneah ppneah pnpeah nppeah pnpeah nppeah penpah epnpah pnepah npepah enppah neppah penpah epnpah pnepah npepah enppah neppah
Note: these 'words' (valid or invalid) are all the permutations of the word happen. These words are obtained by scrambling the letters in happen.