This forg is NOT croaking at all. He is singing. When this video was shot, it was probably mating season. When a male wants to mate, he sings by swelling his pouch. Then, he jumps on the female's back, clasps with his legs,and wait until the mating is complete.Don't believe me??? Check out this book...Frogs: Living in two worlds By: Andrew Llamas
singing/croaking - I have never heard of any specific distinction for croaking other than it being the sound made by a frog, not the purpose of the sound.