So, here is a Littlebigplanet + Star vs the Forces of Evil crossover:
So, the people living in Bunkum are the magical creatures, and the people in Craftworld (including Sackboy and Sackgirl) are the humans
I'm thinking Newton would be Star. Newton and Star are clumsy, but they are very strong. The wand would have the titan's magic in it.
Sackboy is Marco because why not. Also, Marco and Sackboy know how to fight. And they are a little smart. They are nice too.
And Sackgirl would have to be Jackie. Jackie x Marco is basically Sackboy x Sackgirl I think. Jackie and Sackgirl are both girls. They are cool and nice too.