The Caterkiller is a type of Badnik created by Dr. Eggman. First appearing in the original Sonic the Hedgehog game in 1991, it is modelled on a real-world caterpillar. Caterkillers are designed primarily for defensive purposes rather than attacking head-on; their bodies consist of multiple segments adorned with spikes that scatter when the robot is destroyed, creating widespread hazards on the terrain.
The Caterkiller is a Badnik modelled after a caterpillar. Its form consists of a round head adorned with a pair of antennae and three spherical segments that make up the body. These segments each have a sharp metal spike on either side of them, making it dangerous for Sonic to attack any part other than the head.
Originally, Caterkillers could only move slowly by squirming forward, gnashing their fangs constantly as they did so. Dr. Eggman has since made numerous modifications to the Caterkiller and built several variants possessing deadlier abilities.
Sonic the Hedgehog (1991)
In their debut appearance, Caterkillers would be encountered in both the Marble and Scrap Brain Zones. They would slowly crawl forward along the terrain and had no other form of attack, but they would often appear in confined spaces where Sonic could not jump over them and would have to go through them. While the Caterkiller is constantly biting while crawling, this poses no threat to Sonic. As for defeating a Caterkiller, the best option is for Sonic to perform a Super Spin Attack and roll into its face rather than risking a jump. If Sonic hits the Caterkiller's body instead of its head, not only will he take damage but the Caterkiller's body segments will scatter and bounce around the level.
Sonic 3D Blast
An unnamed Badnik appearing near-identical to the original Caterkiller features in the Green Grove Zone in Sonic 3D Blast. What sets it apart from many of the enemies in the game is that it is one of the few that takes offensive action against the player. In some sections of Green Grove, Sonic will come across a pair of holes in the ground parallel to each other and the Caterkiller will repeatedly leap from one hole to the other. Sonic must time his jump attack just right to hit the Badnik's head and destroy it as he will take damage it he touches the body.
Sonic Lost World
Caterkillers make a long-awaited return in the 3D game Sonic Lost World. There are two particular types of Caterkiller in this game: the first is essentially the original version from Sonic the Hedgehog (1991), although it is slightly larger and has an additional body segment. It is found in Windy Hill and Silent Forest and crawls slowly along the ground of whichever planetoid it is stationed on. To attack and defeat it successfully without taking damage himself, Sonic must execute a Homing Attack or Bound Jump while targeting its head. If Sonic hits any other part of the body, the Caterkiller will be destroyed but Sonic will also take damage while the Caterkiller's segments will scatter over a short radius and then remain where they stop.
The second type of Caterkiller is quite different to the first; it is coloured pink and has distinct eye-lashes, giving it a feminine appearance. More importantly, this Caterkiller is enormous in size and is capable of quickly burrowing through the ground and lunging out to attack. It can even leap from one planetoid to another, tearing apart the terrain as it does so.
Sonic encounters these giant Caterkillers in Sky Road Act 1 where he must fight them in order to progress. The Caterkillers will attack by bursting out of the ground and attempting to crush Sonic by slamming their heads down upon him. When their heads hit the ground, they generate shockwaves that Sonic must jump over to avoid taking damage. Sonic can defeat the giant Caterkillers by attacking their heads, but can only use Focused Homing Attacks or Flying Kicks to do it as any other attack will result in him being hurt. It takes six Flying Kicks or two to three Focused Homing Attacks to destroy a giant Caterkiller.
Sonic the Comic
In the Sonic the Comic series published by Fleetway Editions, the Caterkillers were a part of Dr. Robotnik's Badnik army. Because of the different artists, Caterkillers were often give a slightly different look in each of their appearance. Despite having a strong bite, Caterkillers were not smart in their early appearances, but over time, later models got faster and were able to burrow through the ground.
The Caterkillers were frequently called into battle against the Freedom Fighters and their allies. While he was stationed on Flickies' Island, Robotnik started building a more powerful and ferocious-looking model of Caterkillers.
In the Sonic the Hedgehog comic series and its spin-offs published by Archie Comics, the Caterkillers were among the first generation of badniks produced by Dr. Robotnik. The Caterkiller was in fact the first Badnik Sonic the Hedgehog encountered. Over time though, the Caterkillers were rendered obsolete by more advanced robots. When Dr. Eggman took over, he would go on and produce a far larger and more powerful, but also less intelligent, Caterkiller.
Following the events of Worlds Collide, the Caterkillers' history became nearly identical to that of their game counterparts. In Another Time, In Another Place, different type of Caterkillers called Goal Caterkillers were built by Dr. Eggman to kidnap Sonic's friends.
- In the Japanese instruction manuals for Sonic the Hedgehog and Sonic & Knuckles, the Caterkiller and Sandworm Badniks are both named "Nal". This confirms that both Badniks are meant to be the same model.
- A mechaniloid enemy by the name of Caterkiller appears in Mega Man X3.