It's a stuffed old green tomato.

The story:

I used to work at the day care at my gym and we could hear the
music the instructor would play during the routine.This was one of
the songs and one day I realized the kids were singing along to it
with this interesting take on the lyrics!
I know adults aren't supposed to laugh at little children but it was
the funniest thing I'd ever heard and to this day I laugh every time I
hear it and sing their version!