This may be a strange question, but does anyone know what kind of tree this could be?
I know, it's just a comic, but these trees, at “walking distance” within that comic are easily identifiable as Grandidier's Baobabs:
(That might indicate, of course, that the above tree also occurs on Madagascar, but it's a comic, so all bets are off. And yes, we know, there are no squirrels on Madagascar.)