The Arm Of Ed Paradox is when Ed , from an alternate timeline had his arm sliced off. This in return caused the arm to fully regenerate into a new being as this alternate timeline works very differently to our own. This Creature was codenamed by Distraction Industries into the 'Arm of Ed' Aka , Ahmed. One day whilst owner of Distraction Industries was skipping through periods if time across multiple vastly different timelines , attempting to eliminate alternative versions of Rhys who were set to diverge from the path of time , he discovered the newly formed 'Arm of Ed' , Upon taking it back to his timeline , the original timeline nicknamed the 'The Origin' or 'Timeline 1' , he replaced the newborn child of a mother ; who was an alternate version of Rhys's mother, he replaced the divergent with with 'Arm of Ed' whose name became 'Ahmed'.
That doctor who episode where his old arm turns into a human is just like the Arm Of Ed Paradox! Crazy