Zoomer, or Shūn (シューン) in Japan, is a kingfisher bird-like Badnik that appears in Sonic the Hedgehog 4: Episode II.
Found in Sylvania Castle Zone, this Badnik flies above the water surface like a hummingbird, and as soon as the player(s) passes underneath it will dart down with a mighty dive until it hits the ground. A Spin Attack can easily destroy them, although running past them fast makes them relatively harmless.
||A newly developed Kingfisher inspired robot. It usually flies over the water surface, but as it finds Sonic and Tails underwater, it will dart down at them.
— Sonic the Hedgehog 4: Episode II website