Here's a growling Budgett's frog:
YouTube - Deadly Mexican Staring Frog of Southern Sri Lanka

And a growling Fantasy Frog (Ceratophrys cranwelli hybrid with C. cornuta)
YouTube - Pissed off Fantasy Frog in HD. Volume up.

(Note to anyone watching this - don't use small gravel like that with your frogs because they can swallow it accidentally and it can cause a blockage in their gut, known as an impaction, which can kill your frog)