The Test Robots are the central antagonists in the Nintendo DS spin off The Elite Penguin Force. They were robots that were created by Gary in Club Penguin: Elite Penguin Force which became corrupt and evil and were responsible for creating The Ultimate Proto-Bot 10000.
In order to help him out with some inventions, Gary created three robots each with their own unique and special abilities. However, the robots eventually became corrupt and escaped from the HQ. Gary attempted to track them down however he was injured after a mine cart accident.
After the player found him and rescued him, allowing him to heal from his amnesia, Gary explained what had happened. Various items around the island began to go missing by this point and it was later revealed that this was being done in order to create the Proto-Bot. The EPF found one of them attempting to steal the Gift Shop Vault, however they deactivated it.
Later however the Snow and Jet bots began stealing more items leading to them having to be deactivated as well. The EPF celebrated their victory until The Ultimate Proto-Bot was revealed and almost took over the island before being stopped by the EPF. They later appeared in their own level of System Defender (a game on the website) as the main antagonists, but their plan to hack and corrupt the EPF computer systems and machinery failed here as well, leading to them fleeing.
The possibility of them returning will sadly never happen due to the original game being shut down in favor of the new mobile app Club Penguin Island.