Fluffala size (in diameter): 7,927 miles
Chiyo size (in diameter): 1,802 miles

This pic shows the sizes of Fluffala relative to the size of its only natural satellite Chiyo which is the accepted name by all Flufflamorphkind since ancient times. Fluffala is the blue-green habitable planet on the left while Chiyo is the gray and cratered satellite on the right.

As one can see, the size of Chiyo is large relative to its parent planet’s as well as having a similar orbital relationship to Earth and its natural satellite.