Croach the Tracker has had many alternate versions appear in Sparks Nevada, Marshal on Mars.
Holo-Croach[]
In Danger 2.0, holographic versions of Croach the Tracker, played by Mark Gagliardi, and The Red Plains Rider, played by Busy Philipps appeared. Programmed by Sparks Nevada to comfort himself in their absence, the holoprojections gained consciousness and attempted to kill Sparks Nevada after making him cry mercilessly. Sparks was saved by The Troubleshooter, who fixed the glitch in their programming.
Dream Croach[]
After Croach's accidental death at the hand of Sparks Nevada in Red Alert, Sparks began having nightly dreams of Croach in which Croach would at first chat with him pleasantly, but soon Croach would turn on Sparks Nevada and eat Sparks' guts. One version of Dream Croach in the episode Sweet and Show Down was played by Chris Hardwick, who claimed he was Croach in a "superior body", and made him eggs both with his body and which came from his body. Also a butter he secreted. Another version, in Murder In His Place, played by Mark Gagliardi, was flippant and impatient with Sparks until the guts-eating could commence.
V'Stalu-Inhabited Croach[]
Croach was resurrected by V'Stalu of the Galaxium in Tales of the Troubleshooters - Personal Business. Croach shared consciousness with V'Stalu, and while he claimed to still be 100% Croach while also being 100% V'Stalu, Croach's behavior was wildly different, preaching a message of Peace, Love, Beauty and No-Shoes and refusing to intervene to assist the universe from ending. V'Stalu-Inhabited Croach appeared in several more episodes -- Croach Returns, Support Your Local Marshal and Cactoid Jim, King of the Martian Frontier - Good Jim.
Jib Janeen as Croach[]
In The Thing From This Same Planet!, Croach the Tracker did not actually appear, however, Jib Janeen the Jupiter Spy, played by Paul F. Tompkins, impersonated Croach throughout the entire episode, fooling both Sparks Nevada and The Red Plains Rider into believing he was Croach.
Alternate Reality Dream Croach[]
In Crisis on Infinite Marses, part 2 and briefly in Part 1, the dream version of Croach from Sweet and Show Down was brought into the prime reality from an alternate reality of the Barkeep's creation, where he actually exists. This version of Croach was played by Mark McConville, and was sent back to his own reality by the end of the second episode.
Robot Croach[]
As the Space Saloon's AI glitched several times, causing her to fall in love with Croach even after a hard reboot and being brought back to life by the Barkeep, in Malware Wars, after using what bits of The Force Galactic she could find to thumb through alternate universes to find a version of Croach who loved her, the Saloon found that she didn't have enough power to make it to that universe. Instead, she used her remaining power to steal supplies from the hardware store to build her own robot version of Croach, played by Craig Cackowski. The robot was shot and killed by The Red Plains Rider after becoming aggressive.
Nano-Spore Cloud Mimetic Croach[]
Croach found empathy for The Saloon Doors after she lost her Croach robot. Croach said that he loved the Saloon fractaly, and offered to create a nano-spore cloud to program his mimetic self in the saloon's inter-facial consciousness. This created a new version of Croach which only the Space Saloon could experience, but who loved her back, as the martian himself could never achieve. This version of Croach can be seen only through the Saloon describing him.