Over the years, there have been various incarnations of the Legion of Super-Heroes. It was discovered that the Time Trapper has made countless attempts to separate Superman from the Legion and erase him from the timeline, but these attempts never last. The Trapper claims to have "confused" the Legion with "pocket dimensions and alternate history", implying that he is responsible for the existence of at least three incarnations of the Legion.
The Legion of Super-Heroes (Version 1)
The Legion of Super-Heroes (Version 2)
The Legion of Super-Heroes (Version 3)