Successors, Knock-Offs, and Proteges
OK, this is a list of comic book characters that are knock-offs or successors of other well-known characters. Please note that characters who exist in the future/possible future are automatically successors, regardless of whether or not they actually have the same name as the character they are a successor too. If, however, the character still exists then the character is a knock-off. For example, American Dream is a Captain America Successor, because while she is not calling herself "Captain America" she is filling that role, and Cap is nowhere to be found, so she's a successor. By contrast, USAgent, though he is similar to Cap, exists at the same time as Cap, and therefore, is a knock-off. Finally, if the character both exists at the same time as the preexisting character but is also having that character as a mentor, then the character is a protege instead of a knock-off. IE: Kid Flash is a protege. To keep this list at a manageable length, I chose only hero-related characters. So no villains. I might do a villain version of this list later on though.
Also note that "Knock-Off" is not being used in a negative way here. It is simply being used to describe a character who is based off of another preexisting character. But it doesn't have to be negative.