Question

I want to know what pokemon to use it on.

Comments

It's about time you learn how to use the related questions. See that list of questions to the left of the page? When you type in your question that list shows up. Next time look to see if your question is on there.

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Did I do something wrong? Sorry i'm still a noob to this page :(

Answer 1

Well, without getting too tech-y (jk), it is used to evolve Happiny into Chansey while held and leveled-up.

Look at the source if you'd like more information.
Source: http://www.serebii.net/itemdex/ovalstone.shtml

Hoped this helped!