Since it's a story, especially a cartoon story, these names were obviously chosen for a reason, they have a functional role in the story's events or moral. I would definitely translate them, and put them in between brackets.

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Note added at 4 hrs (2013-07-17 19:28:01 GMT)
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Of course, the case would be different when translating the names of real places, or places in an adult fiction for example.