Unnamed non - humanoids ( 23rd century ) Some unidentified non - humanoid species observed in the 23rd century . Alfa 177 canine . The Alfa 177 canine was a species of dog native to the planet Alfa 177 . It was very similar to an Earth dog , with the exception of a on its head , a scaled backbone , and thin gold e sprouting from its head . In 2266 , a specimen of this species was brought aboard the . After the transporter became infected with a yellow magnetic dust from the planet , the crew unknowingly tried to beam the canine back down to the surface of Alfa 177 . The animal rematerialized as two different dogs : one , very gentle and shy , and the other very angry and dangerous , who would try to bite anyone who came near it , so that it had to be put in a box in the transporter room . After the crew came to believe that they had repaired the transporter , they tried reintegrating the two . Although the procedure itself appeared to be a success , the animal was found dead , possibly due to the shock of reintegration . ( ) The stuffed head of an Alfa 177 canine was on display in Trelane ' s mansion on Gothos . ( ) Background information . This animal was originally to have been " a small , mild sheep - like creature , " described that way in the first draft story outline for . There , the animal was described as being held and briefly petted by Kirk in the installment ' s teaser . In a memo from Robert Justman to Gene Roddenberry ( dated ) , Justman admitted , " " I feel we don ' t need this creature for two reasons . Firstly , I don ' t know how we create this creature , unless we take a dog and shave its hair off in some way or other to make it look different . " " The other reason for Justman ' s reluctance to accept the animal was that he felt its duplication by the transporter revealed to the " Enterprise " crew too early that the transporter was producing doubles of whichever individual went through it , a fact Kirk and Spock were attempting to hide from the crew later in the outline . In the revised story outline of " The Enemy Within " , this animal was initially described as " a small , gentle , dog - like creature . " Also , it was still portrayed as being held and briefly petted by Kirk in the episode ' s teaser . After reading the revised outline , Robert Justman devised a plan that would canon ically account for the animal ' s similarity to a dog . In a memo he wrote Gene Roddenberry ( dated ) , Justman stated , " " I finally solved my own internal problem with determining what the gentle creature is like that Kirk holds , which later appears in the story . " " Justman continued by proposing that , instead of making it an extraterrestrial animal , the writing staff could have the creature be one of multiple " Earth specimens " which were being collected by the " Enterprise " , having been deposited on the alien planet earlier in order to test how habitable the planet was . " " Therefore , the small , gentle , dog - like creature which Kirk holds and pets briefly can , in actuality , be a dog , " " Justman suggested . In two different scenes from the revised draft of the teleplay for " The Enemy Within " ( submitted shortly before ) , the aggressive double of the animal was described as " growling savagely with its fangs bared . " In a later scene , one of the dog - like creatures was rematerialized , then wandered around , a glazed look in its eyes , before it suddenly collapsed in a heap . By 1 June 1966 , two identical - looking dogs were found to play the alien animal , the idea that it be a Terran dog having been dropped . In a memo Robert Justman wrote John D . F . Black regarding a revised draft of the script of " The Enemy Within " ( the memo was dated 1 June 1966 ) , Justman pondered , " " Do you think that something ought to be said in dialogue with regard to the small dog - like creature that North is carrying ? " " Later in the same memo , Justman remarked , " " It is very difficult for us to get two completely matching animals that we can change to make look like space dogs , and yet be trained enough in all respects to give us the varying responses that we need . The two matching dogs that we have found are odd looking enough , once they have been helped by Freddie Phillips . However , it just so happens that neither of these animals will really charge the camera , or anything else for that matter . We can get them to look as if they are snarling and get some barks out of one of them , but insofar as charging goes , I think we ' d better throw that idea away . We might get a little bit , but not too much . Of course , we could solve part of the problems of this animal by establishing [ . . . ] that they have already tranquilized the vicious animal and it is available for work with the others in the Transporter Room . This also solves the problem of shooting the darn thing with a hand phaser and making the audience understand that we have just stunned it and not killed it . Also know you this , that every time we have to show the animal knocked out , it is going to cost us a hundred dollars for a veterinarian and an injection . This , in addition to the cost of rental of the animals and trainer ' s fees . " " Another sequence that Justman , in the memo to Black , doubted the canine performers would be capable of was the weaving around with eyes glazed , then abruptly collapsing on command . As a result , Justman instead suggested the alien creature might be already deceased upon rematerialization . Justman also criticized a subsequent reappearance of the dog , asking , " " Why do we have to see the dead dog in this sequence ? " " The description of the animal in the final draft script of " The Enemy Within " ( dated 8 June 1966 ) was exactly the same as that in the episode ' s revised story outline apart from omitting the word " gentle . " By the time the final draft teleplay was written , the animal was held , at the start of the episode , by Sulu ( who replaced the never - before - seen character of North during the episode ' s development ) and was no longer to be held by Kirk in the teaser , but was briefly petted by him , precisely as happens in the episode . In a letter of script notes from Spock actor Leonard Nimoy to Gene Roddenberry ( dated 8 June 1966 ) , Nimoy commented it was odd that " the death of the dog is connected only to Kirk ' s problem " and implied that he believed the dog ' s death should be more clearly connected , additionally , to the plight of the away team on Alfa 177 . The headpiece of the dog ' s costume was used for the sequence when the dog rematerializes dead , in the failed transporter attempt , and was later reused as one of Trelane ' s trophies . According to " Star Trek Maps " ( p . 22 ) , the species name given to this animal was Canis Alfa . The animal was featured in Jenny Parks ' 2017 book " Star Trek Cats " . Fluffy creature . This creature was capable of generating and controlling energy without causing itself harm . In 2267 , Pavel Chekov listed it , the electric eel , and the giant dry - worm as examples of such creatures when attempting to understand the source of Apollo ' s power , but James T . Kirk interrupted him before he could finish saying the creature ' s name , saying he didn ' t ask the navigator for the whole encyclopedia . ( ) Multi - eyed alien . A painting with a member of this species with many small black eye s underneath two large eyes hung in Dr . Leonard McCoy ' s sickbay aboard the for some time . ( ) Nimbus horses . On Nimbus III , blue horned animals resembling horse s were used as riding animals by the Galactic Army of Light . ( ) Omegan goats . Omegan goats were a type of animal native to Omega IV . These mammal s were characterized by shaggy white fur and two long horns on their foreheads . They were seen in a Kohm village . ( ) Organian goats . Organian goats were a type of animal native to Organia that had a shaggy blue hair . The goats were used by the Organian s for farm ing and general labor during the late 23rd century . ( ) Trelane ' s collection . Alligator - like creatures . The head of two alligator - like creatures with pig - like ears hung on Trelane ' s wall in his 19th century house . ( ) Bird - like creature . An avian looking creature was displayed at Trelane ' s mansion . ( )