Pooh's Rumbly in My Tumbly Song is a song sung twice by him in Winnie the Pooh, once to climb a bee tree and another time while eating honey from it while he was blown into a bee tree after being shot out of Rabbit's front door.
Narrator: And it went something like this
Pooh: Hum, dum, dum dum deedee dumdum, I'm so Rumbly in My Tumbly...off. Time to much some early luncheon, time for something sweet! It's the tasteful thing to do be at 10 or 12 or two for anytime is food time when you set your clock on Pooh time you know that Bears like honey and I'm a Pooh Bear, so I do care, so I climb there, I'm so rumbly in my tumbly, time for something sweet to eat!