Go to the Piñata Encyclopedia and select the piñata that you need unblocked. There should be an unblocking requirement, similar to how there's appear and visit requirements. For example you need a Weedling or two to free the Swanana, etc.
"Grammar molestation should be kept to a minimum." -MutatedMarshmellow
When i first asked this question I had only seen other people's posts saying that he was behind the totem pole. Then when I turned my game back on, I saw that there does seem to be a gate back there but there is no Ponocky. I would happily check the unblock requirements but he hasn't appeared.
I am level 70 and he still hasn't shown up. WHY?!!!
It's really annoying because without the Ponocky, I can't get the Horstacio-Zumbug-Chewnicorn. I really need to know what makes that darn Ponocky appear.