Orbinaut

Two types of orbinaut from Sonic 1.

Orbinaut is a badnik that appears in more than one game. It's a hovering sphere surrounded by four spiked balls which rotate slowly and are used for both attack and defence, and is apparently based on a sea urchin (the Japanese word for sea urchin is "uni").

In the Mega Drive version of Sonic the Hedgehog, there are two types of orbinaut. The first appears in Labyrinth Zone, and is referred to as "Unidus" (ウニダス) in the Japanese manual. "Unidus" is red in colour and launches its spikeballs along a horizontal line when Sonic approaches. The second type is found in Star Light Zone, and is known as "Uni-uni" (ウニウニ) in the Japanese manual. It is green in colour and doesn't launch its spikeballs, making it less threatening but harder to kill. An orange "Uni-uni" also appears in the 8-bit version of Sonic the Hedgehog in Sky Base Zone.

A third Orbinaut appears in Sonic the Hedgehog 3's Launch Base Zone. This version is silver-grey and spins faster when Sonic is moving, but doesn't launch its spikeballs. A similar enemy in IceCap Zone, Star Pointer, does launch its spikeballs.