If you want the largest sound made by an animal that animal is the Blue Whale.
The loudest sound produced on Earth is a volcanic eruption, with the eruption of the Krakatoa volcano in 1883 being one of the loudest recorded sounds in history. In space, the collapse of a massive star into a supernova can produce incredibly loud sound waves.
monkeys
The ten loudest farm animals typically include the following: roosters, known for their early morning crowing; pigs, which can grunt and squeal loudly; cows, especially when mooing; sheep, which bleat vocally; and goats, known for their distinctive bleats. Other loud farm animals are ducks, turkeys, donkeys, geese, horses, and llamas, all of which can produce significant noise levels in various situations. Each of these animals contributes to the characteristic sounds of a farm environment.
elephant
The sperm whale.
Reptiles do not make noise other than a hiss, when angry, except for a very disturbed rattlesnake. This is one reason for their popularity as pets.
The noisiest animals, in water, are Blue Whales. The noisiest animals, on land, are the howling monkeys (ALOUATTA) of central and South America. The howling monkeys can be heard 16 km/ 10 miles away and blue whales can be heard 850 km/ 530 miles away.
A spider's sounds can be very faint and not travel very far, usually only a few meters at most. The loudest sound they produce is typically when they are rubbing body parts together to create a vibration, but even then the sound isn't very loud or travel a long distance.
The blue whale is the largest animal in the world, reaching lengths of up to 100 feet. The blue whale is also one of the loudest animals, producing sounds that can reach up to 188 decibels.
Well It's how you hear it. To me I would it is the elephant but if you are right next to a lion it may be loud.
Dynamic Range
the loudest would be the flowmaster outlaw series. its just a straight through muffler with no ceramic glass packing. i have one on my f-150 it sounds way good