5 Mythical Creatures that really existed,

"Dragons"

Megalania

It is an extinct giant goanna or monitor lizard of the open forests, woodlands and perhaps grassland.

It ate meat, including mammals, snakes, other reptiles and birds.

It was twice as long as it's  nearest living relatives of Megalania, the Komodo Dragon of the Flores Islands in Indonesia.

It appears to have disappeared around 40,000 years ago.

It was said to have lived in Australia.

They could weigh up to 4,280 pounds.

It had poisonous saliva, containing blood thinner, causing it's victim's to bleed to death.

The first aboriginal settlers of Australia might have been a factor in their extinction.

Titanaboa

Over 48 foot long snake known to have lived in Columbia.

It is the largest snake to every have existed.

Weighed up to 2,500 lbs.

The Kraken

Colossal squid

46 feet in length and 1,1650 lbs.

It's limbs are lined with sharp hooks, each having three points.

It has the largest eyes out of any documented animal ever.

It was found a 1,000 kilometers from Tokyo.

They are still alive to this day.

Moby Dick

Sperm whale "Moca Dick"

A male sperm whale that lived in the Pacific Ocean in the early 19th century, usually encountered in the waters near Mocha Island, off the central coast of Chile.
Destroyed over 100 whaling ships.

He was killed in 1838, after he appeared to come to the aid of a distraught cow whose calf had just been slain by the whalers. 
His body was 70 feet long and yielded 100 barrels of oil, along with some ambergris—a substance used in the making of perfumes and at times worth more per ounce than gold. 
He also had nineteen harpoons in his body.

Vampires

Vlad the Impaler"Dracula"

Known as a madman, though in his native land he is revered as a savior from Turkish domination.

He was a Romanian prince

He would torture and kill enemies by impaling them.

He would consume his enemy's blood.

After he died, his body disappeared.