Alfa 177 canine

The Alfa 177 canine is a species of dog native to the planet Alfa 177. It is very similar to an Earth dog, with the exception of a horn on its head, a scaled backbone, and thin gold antennae sprouting from its head.

In 2267, a specimen of this species was brought aboard the Enterprise. After the transporter became infected with a yellow magnetic dust from the planet, they unknowingly tried to beam the canine back down. It rematerialized as two different dogs, one, a very gentle and shy one; the other was a very angry and dangerous one that would try to bite anyone who came near it, so it had to be put in a box in the transporter room. After they believed they repaired the transporter, they tried reintegrating the two. The results were futile, as the dog beamed back dead. 

The stuffed head of an Alfa 177 canine was on display in Trelane's mansion on Gothos. 

Alfa-177-Hund