Why Frog Croaks - S1.E11

You see there was a time when Frog didn't croak. Frog sang like a bird and the birds didn't like it. Birds were the masters of song and that's the way it should be! So the birds tricked poor old Frog into a singing duel and sang and sang and sang until poor old Frog's voice was reduced to a ribbit. Tales from Africa.