Obama's gifts: Crocodile insurance, a donkey

World leaders and White House visitors often bring gifts to presidents -- and some of them are, uh, a little unusual.

President Obama's swag has been no exception, ranging from underwear to a live donkey to insurance against crocodile bites.

The website mental_floss spotlights "6 Weird Gifts President Obama Has Received:"

1. Crocodile insurance, a $50,000 policy covering croc attacks, courtesy of the chief minister of Australia's Northern Territory. Obama himself called it, "the most unique gift I've received as president."

2. 50 pairs of H&M boxer-briefs, from soccer star -- and H&M model -- David Beckham.

3. A $395 pencil, from the president of the European Commission. It's a "Graf von Faber-Castell Perfect Pencil."

4. Customized Red, White, and Blue "Soul" Headphones, from the rapper Ludacris.

5. A donkey named Demo, from the town of Turbaco, Colombia. Obama declined it.

6. A ping pong table, from British Prime Minister David Cameron in 2012. Said Obama at the time: "During my visit to London last year, David arranged for us to play some local students (in) table tennis -- as they would say in Britain, we got thrashed."

What happens to all these gifts?

The explanation from mental_floss:

"A gift's fate comes down to who gave it and how much it cost. If a foreign leader gives a present valued under $350, the president can keep it. But if it costs a penny more, it's considered a gift to the American people.

"The State Department meticulously catalogs the worth of each gift the president receives, and the haul is usually stowed in the National Archives until it becomes part of the presidential library. (If a president really wants one of these gifts, he can purchase it from the American people at market value.)

"If, on the other hand, it's an American citizen who's sent the gift, the president is free to keep it under one stipulation: He has to pay taxes on it. Gifts the president rejects are usually sent to the National Archives or given to charity.

"Don't bother trying to send the first family your famous holiday fruitcake, though; foodstuff gifts are immediately tossed by the Secret Service."