What Pokemon have less CP when they evolve in Pokemon Go?

Question

I evolved a 97 CP Shadow Weedle, and it became a 91 CP Shadow Kakuna. Is this only for Shadow Pokemon, or are there certain Pokemon that have lower CP when they evolve?

Also, please don't question the fact that I evolved that Weedle.

Comments

I’m pretty sure CP works off of a multiplier system when evolving so that could be why but idk so I’m putting as a comment and not an answer

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Weedle, Caterpie, Trapinch and Wurmple are all the Pokemon I know of that gain lower CP when they evolve into their next form(s). I'm pretty sure this has got nothing to do with Shadow Pokemon.

Answer 1

There is actually a Reddit on this, I quote:

This is a quirk that happens with a few Pokemon, like Trapinch, Weedle, and Wurmple. Basically, the CP formula puts more weight into a Pokemon's attack than it does into its HP or defense. In Trapinch's case, it loses a bunch of attack when it evolves, and only gains a little bit in its other stats. So the effect is that its CP drops along with the drop in its attack. When you evolve it into Flygon, its attack will go back up again, and its CP with it.

If this is true, then any Pokemon that fits this condition (loses a bunch of attack when it evolves, and only gains a little bit in its other stats) will experience a drop in CP despite evolving.

Source