Crocbot

Crocbot was Dr. Ivo Robotnik's sub-boss in Downunda during his ten year rule of the planet Mobius. Possibly the most malign of all of Robotnik's creations, Crocbot was perhaps the strongest and most dangerous as well. Showing unprecedented ambition for a machine, Crocbot planned to overthrow Robotnik and rule Mobius himself. Although suffering numerous defeats, Crocbot managed to survive every encounter, resulting in a growing hatred for his enemies, particularly the Freedom Fighters and Tails.

Downunda Campaign
Robotnik sent Crocbot to act as his regional dictator in the southern hemisphere. For years, Crocbot maintained a moderate level of control over the continent of Downunda, though on occasion he would come into conflict with the Downunda Freedom Fighters, which would often spoil his plans. To ensure he had the necessary means to secure control of the continent fully, Robotnik shipped a zeppelin of SWATbots, Combots, weapons and other materials to Crocbot. Prior to its arrival, Crocbot mostly employed his machine flying dingoes. (TMS: #1, #2)

Crocbot's first real defeat came when the Downunda Freedom Fighters received assistance from Miles "Tails" Prower, who had recently embarked on a solo adventure in his Sea Fox. Just as the blimp full of SWATbots and supplies arrived, Tails and Barby Koala attacked, disrupting its docking procedures and causing it to crash. Crocbot then attempted to escape in his nuclear-powered tank, but a bomberang from Walt Wallabee knocked the tank off course, causing it to crash into a crater (the former site of Echidnaopolis) and explode. (TMS: #3)

Revenge
It was later revealed that Crocbot survived, building a prison camp in the crater. The explosion somehow fused Crocbot to his tank, leaving him with tank treads in the place of legs. Backed by an army of Combots, he sought to regain control of the continent. He was able to successfully capture Barby Koala, Walt Wallabee, Antoine D'Coolette and Bunnie Rabbot, and was in the process of mining mineral ore to power Robotnik's Ultimate Annihilator. Still wishing to rule Mobius alone, Crocbot secretly planted a thermo-nuclear device in the airbus which was carrying the ore, hoping to wipe out Robotnik with it. The device was found by Bunnie and stolen for other purposes. Crocbot succeeded in shipping the ore to Robotnik, but came under attack shortly after it left by the other Downunda Freedom Fighters. Crocbot was again seemingly destroyed by the attacking Freedom Fighters. His lower half was completely destroyed as a result of the attack, but Crocbot managed to survive once more. (StH: #50, SSS: #4)

Having planted a post-hypnotic mind control diode on Duck "Bill" Platypus - one of the Downunda Freedom Fighters - during his time in the Downunda Crater Detention Camp, Crocbot had "Bill" to move his remains into hiding. Some time later, using "Bill" as an agent, he convinced the other platypus on Downunda to oppose the Downunda Freedom Fighters. Fortunately, Sonic and Tails soon showed up during their hunt of Ixis Naugus. They discovered Crocbot hidden under a building, and disconnected him from his power supply. Crocbot's remains were shipped to Mobotropolis (which had been retaken by the Mobians by this time), only to be apprehended by Snively's team of convicts, which had recently escaped from the Devil's Gulag. (StH: #61)

Return as Croctobot
On Sonic's 18th birthday, Dr. Eggman dispatched the repaired Crocbot, his bottom half now replaced with the former underwater sub-boss, Octobot. The new menace, now called "Croctobot", began his attack against Freedom HQ, only to be destroyed by the combined might of Sonic, Shadow and Scourge. (StH: #161)
 * It is unknown just how badly destroyed Croctobot was, and whether or not he will return in the future at all is a mystery.

Personality
Crocbot is scheming, manipulative and a brutal commander, whose intelligence is only exceeded by his hatred for the Freedom Fighters. Unlike Robotnik's other creations, Crocbot possesses his own free will and ambition. He one of the most unique and deadly machines in the late despot's arsenal. (TMS: #2, #3)

Background Information
A deleted plot idea would have had Croctobot be the new sub-boss in Downunda and apparently rule the continent once more. This idea seems to have been tossed, and instead, Croctobot made an appearance attacked Freedom HQ on Sonic's birthday. (Sonic HQ 3rd Tier Characters)