[Ruler of the Frogs]

Perhaps they did that to show that Frodo was somewhat weak in the beginning. He didn't know very much. Perhaps by the end, in RotK, you will see him stronger and more noble. It might be a way to show his growth over the course of his journey. Or maybe they want to make Frodo look like a chicken. I don't know, but I think they are just trying to visually present Frodo's change and growth over his quest.