1 Reason Why Evil Morty Isn't Rick's Original Morty (And 5 Why He Is)

Once again, in the episode Close Rick-counters of the Rick Kind we're fed more information than would ostensibly be useless if the Evil Morty being Rick's original Morty theory weren't true.

When the day has been saved and both Rick and Morty C137 are headed back to their own dimension, Morty is angry with Rick for not caring about Morty. Though in his own way he rebuffs this accusation by saying that he is the Rick-est Rick, and that if that is true then Morty would be the Morty-ist Morty.

Seeing that Morty seems to like this, Rick warns Morty against the dangers of a cocky Morty, saying it can lead to some very bad things happening. When Morty questions this, Rick simply replies that he'll tell him when he's older.

This can be taken a number of ways. One of which may indicate that Evil Morty is slightly older than the other Morty's in the universe, though that isn't an accepted theory. Another thing that can be taken from it, is that something went wrong in Rick C137's past that gave him the awareness of that specific danger.

The fact that we cut to Evil Morty's reveal directly after this sequence gives credence to that being true.