Big Wide-Mouthed Frog R/I (Revised)

I’m a big wide-mouthed frog and I eat flies, says the chirpy big wide-mouthed frog to the kangaroo, the koala, the possum and the emu. Who are you, and what do you eat? Then the frog meets a crocodile - and finds out that sometimes it’s better to keep your big wide mouth shut!