This can not end well...

Instantly remembered this

You must use both the Third Leg in combination with the stool to reach the banana.

Black_Gold_Saw said:

You must use both the Third Leg in combination with the stool to reach the banana.

Or, simply fly and take the banana.

Shoot the rope with the arm cannon to get a baked banana.

-"Stool" is a misspelling of "fool".
-Only fools misspell.
-Therefore, the stool must really be a fool.
-Cirno's the biggest fool here, so that stool must be Cirno.
-Hit Cirno with a nuclear blast.
-Cirno is now emitting several bananas of radiation. (http://en.wikipedia.org/wiki/Banana_equivalent_dose)
-Use the Control Rod to remove the radiation.
-You now have loads of bananas.

-Trade them for a bigger stool.
-Take banana from rope.