"Weebles wobble but they don't fall down" was an advertising slogan (song/tune) for a toy, called a 'weeble'. It was in the shape of a small egg, about the size of your thumb, and it didn't fall over when you knocked/hit/pushed it. It wobbled back and forth.
"Watusi" is the name of a dance, and it's the name of an African tribe.
- For Teachers