Melbourne teenager's feet won't stop bleeding after sea creatures "ate through his skin".

There is no shortage of creatures that can cause you harm in Australian oceans. There are the toothed variety. The stinging variety. And, now we know… the vampire variety?

A Melbourne teenager has emerged from the ocean with his lower legs and feet dripping in blood. Stopping the bleeding proved near-impossible and experts have no idea about the creatures that caused it.

Sam Kanizay, 16, went for a swim at Dendy Street Beach in Brighton in Victoria on Saturday afternoon. His muscles were sore from football practice and he thought a cold dip might help alleviate the pain, AAP reports.

Half an hour later, he walked out of the ocean dripping in blood. He didn’t realise it was blood at first, he thought it was sand stuck to his feet, so he went back into the ocean to clean them off.

The ten-year-old who surfed with a shark. Post continues below.

“He went back to his shoes and what he found was blood on his legs,” his father Jarrod Kanizay told AAP. “They ate through Sam’s skin and made it bleed profusely.”

Nothing they did could stop the blood. “As soon as we wiped them (his legs) down, they kept bleeding,” Jarrod said.

The pair went to the hospital where staff were similarly dumfounded.

"There was a massive pool of blood on the floor (at the hospital)," the teen's father said. "No one knows what the creatures are. They've called a number of people, whether it's toxicity experts or marine exerts and other medics around Melbourne at least... (and) yep, no one (knows)."

Jarrod returned to the beach to gather a sample of the specimens so experts can run tests. How did he retrieve the sample? A pool net filled with meat.

"What is really clear is these little things really love meat," he said.