Ruling Pidgey TM + Mew Prime

[Avacado]

+

If i LZ pidgey with Mew, and use Messenger do i shuffle mew back to my deck or is it only refer to "Pidgey"

 

[Sleeping Snorlax]

Yes, you would shuffle mew back in. When the card states pidgey, it is referring to that card. Which is why starting in BW they changed the wordings used in attacks. They say things like "shuffle this Pokemon back into your deck."