Capricious

Definition:
A capricious tone is one that is carefree, where the
narrator is often given to flights of fancy and whim. 
Ex:
I made myself a snowball
As perfect as could be.
I thought I’d keep it as a pet
And let it sleep with me.
I made it some pajamas
And a pillow for its head.
  Then
last night it ran away,
  But
first—it wet the bed.
-- “Snowball” -- Shel
Silverstein
Visual: