I want to make something similar to this, but I can't figure out what the perspective is called. It seems like it is an aerial perspective maybe, but it's not quite looking straight down. Can someone help me figure this out?
Strictly speaking this isn't a perspective projection but a mix of different parallel projections. (In perspective projections objects that are far away appear smaller than objects that are nearby, and that doesn't happen in this drawing.)
The landscape and the houses are drawn in the kind of orthographic projection which is called axonometric projection and specifically it's called trimetric projection because the three axes of space appear unequally foreshortened. (Isometric projection, as mentioned in another answer, is another kind of axonometric projection where the three axes of space appear equally foreshortened. There is also a kind called dimetric projection where two of the three axes of space appear equally foreshortened.)
The trees and animals are simply drawn in side/front view.
The drawing is cut off in the top, which gives the impression of a horizon. Axonometric drawings don't have a horizon, but just continues endlessly.
There is a good article with many illustrations on Wikipedia about 3D projection.