Orbinauts are said to be based off sea urchins (uni in Japanese). Orbinauts are different colors of metal orbs which are able to hover in the air. This badnik's signature weapons are four spiked balls that ringed around of them. Some of Orbinauts throw at its prey which is its only method of attack for some of these badniks. This is also a major weakness; as once all four spiked balls have been thrown, the hovering Orbinaut itself is completely defenseless.
However some of Orbinauts don't throw its spike balls away, but keep moving forward and keep ringing its spike balls at same time as keeping its defense on. Usually it's impossible to defeat these types of Orbinauts without getting hit, which is good to avoid them and keep moving on. Few of Orbinauts utilize its spike balls with different methods to stop the player.
Uni Uni (ウニウニ) is a green variety of Orbinaut that keeps the four spiked balls around it for defense. It appears in the Star Light Zone from Sonic the Hedgehog and can only be defeated while Sonic is invincible or time your hit very carefully (or when Sonic takes a hit, he has a quick moment to hit it when he's flashing). It also appears in Aquarium Park in the Nintendo DS version of Sonic Colors and in Sonic the Hedgehog 4: Episode I. Like Unidus, Uni Uni is named Orbinaut in the English version of Sonic the Hedgehog.
Star Pointer, later known as Icedus (アイスダス,Icedus?) in Japan, appears in the IceCap Zone from Sonic the Hedgehog 3 and has four spiked ice balls around it. It sends the spiked balls forward to attack. Unlike projectiles from other variants of the Orbinaut, the ice balls will be destroyed with no ill effects to the controlled character if they have any shield or hitting contact with Knuckles' knuckles.
Orbinaut (Pola ポーラ) is a metallic gray variety and appears in the Launch Base Zone from Sonic the Hedgehog 3 . It keeps the four spiked balls around it for defense, and only move when the player also move. It can only be defeated while the player is invincible or with a well-timed Insta-Shield move by Sonic (or when Sonic takes a hit, he has a quick moment to hit it when he's flashing). Though the latter is hard to pull off, it is possible with correct timing.
Flamer, or Bohla (ボーラ,Bohla?), is the latest, different kind of Orbinaut from Sonic the Hedgehog 4: Episode II. Flamers are yellow and have spinning flamethrowers. Flamers can be found in Oil Desert Zone and can temporarily ignite fire of oily landscape.
Gola-type Orbinauts also become temporarily part of E-series as E-17 Ghora appears at Lost World and Red Mountain in Sonic Adventure while E-31 Gola has been featured at Death Chamber in Sonic Adventure 2.