The Lion isn't king of the jungle. It is king of the grasslands.

Lions are actually native to the grasslands of Africa known as the savanna. None live in the jungle (or sleep there for that matter).
(source)

It's not possible to swallow your tongue.

This is a common misconception that is frequently associated people who suffer from epilepsy. It is impossible for a person to swallow their own tongue because tongues are rooted to the floor of our mouths by a segment of mucous membrane called the lingual frenulum.

Don't place an object behind the tongue to prevent someone from 'swallowing' their tongue. This only serves as a choking hazard. In reality, choking is a main risk with this sort of episode - a seizure victim should be placed on their side in order to prevent saliva or other bodily fluids from blocking their airway.
(Sources: 1, 2)

Smoking can shorten a man's penis.

The effect is similar to smoking's effect on a person's heart. The blood vessels within the penis are constricted, which allows for decreased blood flow. This lessened flow has a negative effect on the elasticity of the penis and prevents it from achieving its full length once erect. Studies have shown that over time, these effects can reduce the overall length by as much as 1 cm!

According to one researcher, smoking has more direct harmful impact on the penis than it does on the heart!
(source)

You can EAT GOLD!

Since the 16th century, Europeans have included gold leaf in special varieties of liquor such as Goldschläger from Switzerland and Danziger Goldwasser from Poland. Many Asian countries also enjoy it in such food and drink as jelly snacks, coffee, and tea. You can also have it on sushi, on chicken, on a bagel with truffle cream cheese, or in champagne.

The science behind it: Gold is considered non-toxic in its metallic form. This is because it is resists reacting to any chemical process in our bodies. However, this also means that gold has no flavor or nutritional value, and it passes through your body unaltered. (It's the same going out as it is coming in!)

A warning: while in its metallic form it is non-toxic, gold salts such as gold chloride are toxic to human livers and kidneys. Also, some people are allergic to gold.
(Sources: 1, 2, 3)

Baby giraffes fall 5-6 feet to the ground when they are born.

As the tallest land mammals, adult giraffes unsurprisingly also have really long legs. This is no picnic for their newborn babies, however. They enter the world to a fall of up to 6 feet!

After about an hour, the calf is able to stand up. It's able to run with its mother after 10 hours of being born, and in four months' time it will be able to eat leaves.
(Sources: 1, 2)