[quote=@starfox365]
So interested.

Since there are sloths, I assume the fauna range in the rainforest.

In that case, would it be acceptable to create a Fossa type character? 
[/quote]

Fossas are fine.  There will be a range of ecosystems within the World Tree so the fauna are not purely tropical.  Branches farther away from the center of the tree will be cooler as will those near the poles.