Scorpius is a gigantic and orange colored robotic scorpion, with Robotnik's face as its head. It has four mechanic legs and a large tail that drips droplets of green liquid. Once Sonic collects the three Chaos Emeralds within Toxic Cave, the room to Scorpius opens and Sonic can battle against it.
Scorpius has an extensible tail, which it can use as a shield and to drip poisonous liquid from the tip. Sonic must jump into the gap between the tail and the body in order to attack the body from within; if he succeeds, he will bounce repeatedly within Scorpius and cause significant damage, unless he slips out of the gap, and must therefore reenter it again. After a huge amount of hits, the tail will break off and Sonic can attack Scorpius' body directly, with four hits being needed to destroy Scorpius. There is also an alternate method of destroying Scorpius by hitting the four targets above the ceiling, which will cause a pile of rocks to fall down and damage the Scorpius. The player has to bounce on the tail in order to reach all four targets.
During the first part of the battle, the player can also use the Sewer Warp below the platform (where Scorpius is standing on) to warp above the Scorpius. If Sonic falls to the bottom of the boss room, he will be shot back up, so he cannot leave the room until Scorpius is defeated. The shooter, however, disappears once Scorpius's tail is destroyed, and since the minecart is no longer there, Sonic will fall all the way back to the beginning of the level.
In other media
Adventures of Sonic the Hedgehog
In Adventures of Sonic the Hedgehog, Scorpius (that is called as Boss Scorpion) appeared in the episode "Attack on the Pinball Fortress". Even though the design of it is drastically different, it features two television screens on its eyes, where Robotnik is able to see and control the action. Despite the Boss Scorpion being sustainable kind, Sonic is able to defeat him by spinning around and making the Boss Scorpion shoot terrain crack open, causing it to fall down the lava pool.
In the Sonic the Hedgehog comic series and its spin-offs published by Archie Comics The Scorpius made a small appearance in Sonic the Hedgehog #6. Its appearance is nearly the same with the exception of having six legs instead of four. In this media it attacked Sonic, but was easily dispatched along with his ally, Rexxon.
- The tail of Scorpius is able to get glitched, if the player passes over above the robot at the same time, when tail's turning animation happens. This can cause Scorpius having two headed tail.
- The screech Scorpius lets out when being damaged is the same as Robotnik's in the ending of the final level of the 18-bit version.