A close up of a Khon mask July 8, 2011 in Angthong, Thailand. The paper mache Khon masks, are part of the ornate glittering costumes used in the stylized classical Thai dance form known as Khon. (Photo by Paula Bronstein/Getty Images)

A participant runs through foam during the Love Foam Run race in Hsinchu, Taiwan May 29, 2016. (Photo by Tyrone Siu/Reuters)

Lioness and hyena posture to one another, in Masai Mara, Kenya, August 2015. A photographer captured one of the oldest rivalries in the animal kingdom as a pair of lions went head to head with a pack of hungry hyenas. (Photo by Ingo Gerlach/Barcroft Images)

With more than 40,000 followers on Twitter and 26,400 fans on Vine, it looks like Marutaro the hedgehog from Japan is one of the most popular hedgehogs on the Internet. And as his owner keeps on posting Marutaro’s pictures online daily, Marutaro’s popularity continues to grow. There are hundreds of cute photographs and videos of this little fellow, but the ones with little paper cut-out faces are probably the cutest. As Marutaro lies on his back, his owner gives him a variety of silly expressions and smiles. The 20 best of them will definitely boost your mood!

A Russian digital artist Svetlana Petrova has taken her love of cats to the next level – by adding her furry friend to some of the world's greatest artwork. Svetlana has placed photos of her tabby, called Zarathustra, posing alongside the most well-known pieces in history for her UK exhibition. (Photo by Svetlana Petrova/Zarathustra the Cat)

Revellers take part in the Holi Party Festival at the Niemeyer Center in Aviles, northern Spain, August 29, 2015. The event is inspired by the Hindu Holi spring festival of colour celebrated mostly in India but has recently spread to other countries. (Photo by Eloy Alonso/Reuters)