The word puppy used is 입니다 (immida) , 이다 means “to be” . Since it's a verb, it changes from ‘is’, ‘am’ and ‘are’ depending on the subject in the sentence. In Korean you gave formal speech and informal speech , when you use formal you would say what puppy said 입니다 and not 입니.
For me what was funny is that Puppy's sentence formation was either weirdly constructed or he was trying to be very declarative (since sentences imply the intent of the speaker - i.e.. interrogative, declarative, imperative, or suggestive.) since he didn't use the word "They" when answering Kim Gura's question...which is funny since he was using formal speech, had he not added the 입니다 it would have sounded more normal..