How do you take a picture of Mew?

He is at the last stage,then you can take his picture.

During the first round when you enter Raindow Cloud, it'll have a shield and hover in front of you without passing; hit the shield three times. In the second round it will have a yellow shield and try to pass you; hit it three times total and this shield will disappear. Now Mew will be seen in plain view chasing its shield, and you'll be able to snap a picture. However, if you want a good shot of it, throw an apple or Pester Ball at it to force it into a pose in front of you for three seconds before it disappears and starts chasing its shield again. If it disappears whilst chasing the shield, it will appear in a shield in front of you and try to pass you, whereupon you'll have to hit the shield once to destroy it. This pattern repeats for the entirety of the level.

You throw pester balls at it, and then, it will come towareds you, throw more pester balls, and it will case it's sheild, thow appel at it, snap it when it stops spinnign, repeat

When you get to Mew hit it with an apple or a pester ball to knock off his sheild then SNAP!

Just go to Rainbow Cloud and prepare to use your pester balls and apples.

Ok keep on hitting it's shield the ball it will break adventually then when it breaks take a picture of it.

I used the flute and the shield will vanish with Mew still on the screen (this method is much easier) Hope I Helped!!!