Things You'll Need
Instructions
Purchase pokeballs if you don't already have some. The more you have, the better your odds of successfully capturing the Munchlax. Have at least 10 on hand.
Travel to Floaroma Meadow, which is to the north of Floaroma Town between Routes 204 and 205.
Speak with the Honey Man and purchase a Jar of Honey. The more you purchase, the better your odds of catching a Munchlax.
Go to a Honey Tree. These trees are located throughout Sinnoh. You can distinguish them from other trees by their golden yellow leaves.
Press the "A" button while you're facing the Honey Tree. When it asks if you want to apply honey, choose "Yes."
Wait six to eight hours. If you want, you can turn off the game and do something else, or you can play for the full time.
Return to the Honey Tree. If you're lucky, you'll see a Munchlax standing by it. Of all the Pokemon that are attracted to honey, the Munchlax is the least common to appear. If you're unlucky, you won't have attracted a Munchlax. Apply a new coat of honey to try again.
Face the Munchlax and push "A" to initiate a battle. Attack it until its health is yellow or red, and then throw pokeballs at it until you catch it.