Planet of the Dead " Under the command of Captain James T . Kirk the Starship " Enterprise " held a steady course through the Zeta Stentor system , en route for the planet Selkye . On board the great ship was a party of scientist s and technicians whose mission was to set up a base on Selkye and investigate its possibilities for colonization by mankind . " Summary . As the " Enterprise " arrives at the uninhabited planet Selkye , Captain Kirk ' s new friend , Professor Richard Spellman , informs him that the world should be ideal for colonization . A landing party including Kirk , Spock , McCoy , Professor Spellman , and his team take a shuttle to the surface . It sets down in the ruins of a city , and the crew marvel at the ruins , evidence of a dead civilization . Exploring the relics , Professor Spellman ' s assistant , Professor Ravel , is started to discover a corpse - like creature sprawled on the ground . Resembling a humanoid toad , it has an appearance of having been dead a long time , yet shows no signs of decomposition . Eight of the toad - creatures are found . As the crew discuss the carcasses , some small furry animals crawl over to them . They have no visible eye s , mouth , or legs , and move by stretching and contracting . The crew take an instant , irresistible liking to them , and McCoy takes one as a pet , naming it Beavo . The " Enterprise " crewmembers return to the ship , bringing along a toad - creature for study . Kirk puts the creature in a storage cupboard , and McCoy notes that Beavo likes everyone but Spock . The ship departs Selkye for its next mission , and Doctor McCoy sets about to complete some paperwork , Beavo in hand . After a few hours , he feels unusually tired , and decides to turn in for the evening . At the same time , the withered toad - creature in storage begins to change in appearance , vigor returning to its withered form . The following morning , McCoy awakes , feeling drained instead of refreshed . Spock meets up with him and , despite the Doctor saying he is only tired , Spock thinks he is sick and reports it to the Captain . Kirk , Spock , and Uhura go to McCoy ' s quarters . McCoy insists he is fine , but Uhura takes Beavo to look after . As Kirk , Spock , and Uhura walk through a corridor , they pass the storage cupboards . One of them bursts open , and the toad - creature leaps at the startled crewmen . Spock grapples with the beast , and Kirk grabs a phaser , stunning it . He orders the toad put back into storage with guards posted . Returning to Selkye , Kirk , Spock , and a weakened McCoy take a shuttle back down to the ruins . The Professor ' s engineer s have already assembled a structure and are inside . Approaching the building , the crewmen are attacked by more toad - creatures , and Spock covers his friends ' entrance by stunning the horde of toads with phaser fire . Inside , the researcher team has all been struck with a mysterious illness . The sickened scientists lament that as they grow weaker , the creatures outside are getting stronger . Kirk and Spock go back outside , and phaser every toad - creature in sight . Kirk calls up the " Enterprise " , ordering Scotty to send down the ferry , so that all of the research team can be evacuated . Scotty says that he can ' t send the ferry until morning , as six crewmen have been injured . The toad - creature in storage had escaped once more , and went on a rampage until Scotty disabled it . He also reports that Uhura is now sick , with the same symptoms as Doctor McCoy . Kirk then realizes what is happening , and gives Scotty further orders . Handing Spock a metal container , he instructs him to gather up all the beavos among the researchers . When dawn arrives and the ferry lands , Kirk and Spock leave the compound ; all of the toad - creatures outside once again appear dead . Back on the " Enterprise " , Scotty informs the Captain that he followed his instructions ; he picked up Beavo with metal tongs and stored him in a metal box . Back on the bridge , Kirk explains what happened to the recovered crewmen and researchers . He says that the beavos were not lifeforms at all . Each toad creature possessed a beavo that sought out sources and transferred the absorbed life force through space to the creatures . They had found no other forms of life on Selkye because the beavos had drained the life from them . Kirk offers the researchers the consolation that their experience has added to man ' s store of knowledge . Memorable quotes . " " I ' ll put this mummified toad in store cupboard " B " . . . and keep the door locked ! " "