The Duck Hunt Dog is one of the most minor characters in the series, and his impact on the plot seems to be very little. He is definitely more noticeable than Megaman, especially after he was confirmed for SSB4. His role in the story changes from time to time, whether he is a minion of Toad or Kirby's pet dog.
The Duck Hunt Dog is very playful and annoying. He always appears to be very happy and is never seen to express any other emotions. His reaction towards characters vary widely, whether he is aggressive or well-behaved. He is very easy to tame, but he spends a lot of time just wandering around.