You don't need to be afraid of this crocodile

Evolved to just eat fish, it poses minimal threat to humans with its extremely long, thin snout.

https://en.wikipedia.org/wiki/Gharial

Eels are kind of like Aliens. You know, from the movie Alien?

http://en.wikipedia.org/wiki/Moray_eel

They have a second set of jaws inside their mouth that they use to drag food in once bitten, since they can't swallow like many other animals using suction.

From weapon of war to weapon against cancer

Mustard gas, infamous for its role as a chemical weapon in WW1, was used to develop the first chemotherapy drug.

https://en.wikipedia.org/wiki/Sulfur_mustard

Deathbed confessions are legally acceptable, even if you don't die

http://en.wikipedia.org/wiki/Dying_declaration

Under the Federal Rules of Evidence, a dying declaration is admissible if the proponent of the statement can establish:

1. Unavailability of the declarant -- this can be established using FRE 804(a)(1)-(5);
2. The declarant’s statement is being offered in a criminal prosecution for homicide, or in a civil action;
3. The declarant’s statement was made while under the belief that his death was imminent; and
4. The declarant’s statement must relate to the cause or circumstances of what he believed to be his impending death.

The declarant does not actually have to die for the statement to be admissible, but there must be a genuine belief that death was imminent and the declarant must be unavailable to testify in court. 

The original Siamese Twins

"They were joined at thesternum by a small piece of cartilage. Their liverswere fused but independently complete."

Born in the early 1800s, they graduated from being a curiosity tour attraction to having normal lives, including moving to the United States, marrying two sisters and having slaves.

Due to disagreements between the wives, they eventually had to live in separate households (they split their time between them). Their sons even ended up serving in the Confederate Army during the Civil War.

http://en.wikipedia.org/wiki/Chang_and_Eng_Bunker

Chess in pairs... with a fun twist

Bughouse Chess is a chess variant where two teams of two players face off against each other. Captured pieces on one board may be placed by their teammate, on their teammate's board, in place of a normal move.

"Partners are normally allowed to talk to each other during the game. They can for instance ask for a specific piece, for more trades, ask to hold a piece, suggest moves or ask their partner to stall. Shouts like "Knight mates!" or "Give me pieces!" are common, and can lead to seemingly absurd sacrificial captures on the other board."

http://en.wikipedia.org/wiki/Bughouse_chess

John McCain- even tougher than you might think

It's well known that McCain was a POW during the Vietnam War.

However, did you know that he refused to accept an early release when offered, despite serious injuries and illness?

"..the North Vietnamese offered McCain early release^[44] because they wanted to appear merciful for propaganda purposes,^[45] and also to show other POWs that elite prisoners were willing to be treated preferentially.^[44] McCain turned down the offer; he would only accept repatriation if every man taken in before him was released as well. Such early release was prohibited by the POW's interpretation of the military Code of Conduct: To prevent the enemy from using prisoners for propaganda, officers were to agree to be released in the order in which they were captured."

http://en.wikipedia.org/wiki/John_McCain#Prisoner_of_war