Millions of years ago a creature with 276 teeth and a jaw which could crunch through the biggest dinosaur swam in our oceans.
Megalodon, the largest shark that ever lived, is the star of an exhibition at Kelly Tarlton's Underwater World.
This marine monster is believed to have weighed 75 tonnes and measured 16m in length. It would have made a quick meal of a great white shark and needed more than 1000kg of food daily.
Young visitors were clearly excited by the motorised shark-head and the opportunity to climb inside a giant, pink, rubbery Megalodon mouth.
Joel Ashwell, 4, struggled to reach the top of a huge dorsal fin rising out of the floor.
He was too scared to climb into the replica head but said if he saw a Megalodon swimming in the sea he would "feed it some shark tuna".
Siblings Bella Kingi, 11, and Joel Kingi, 8, agreed that if the "really big" sharks were still alive they would get out of the water quickly.
Shark skeletons are made of cartilage so there are no fossils, but researchers recreated the jawbone by working from fossilised teeth.
The exhibition runs until October 26 and entry is included in the Underwater World admission price.