Miniature horses are extra tiny to begin with (averaging just 30-34 inches high at maturity) but since the little guy in this video is just a baby, he's even tinier than a full grown mini. He already loves to chase people around and have some fun while his mother Grace stands by. This little guy is quite adventurous, especially at his young age.
He seems to love attention too; check out his little tail wagging when he catches up to the person and gets some back scratches! Part 2 of this video is also shown below; the video picks up a bit at the 1 minute, 45 second mark. As these videos were filmed a couple years ago, this little guy is likely around two years old now.
For more videos of this little guy, check out their YouTube channel.