Gigantor

Actually the theme song for Gigantor had no rhymes in it at all. There was the chorus: "Gigantor" (2x)

followed by: "Gigantor the space age robot, he's in your control, Gigantor the space age robot his power is in your hands"

followed by the chorus again.

I don't recall any other verses but what do you expect from such an early import. The transition from Japan to here of this cartoon was equal to other early imports like Kimba, though perhaps less refined than Speed Racer. As to plot I have no recollection only a warm hint of a memory. But this was not from SciFi airings but from the original run on television.