If you see this “unexpected visitor” knocks your door one day, what will be your reaction?

Giant George, a Great Dane from Tucson, AZ, stands 3 feet, 7 inches tall from paw to shoulder, was awarded two titles namely “Tallest Dog Ever” and “Tallest Living Dog” by the Guinness Book of World records on February 15, 2010.

It’s height is three-quarters of an inch taller than his closest rival, Titan, a white Great Dane from San Diego. The photo below shows Giant George and its owner David Nasser.

Hit the jump for more photos of world’s tallest dog Giant George.

National Geographic photographer Andrew Evans recently spotted this “one in a zillion kind of mutation” all black King Penguin on the island of South Georgia, near Antarctica. Apparently the all-black coloration is unheard of in penguin’s coats.

Ten pets from Battersea Dogs & Cats Home in London were selected as the “stars” in a set of Royal Mail’s first-class stamps to mark the home’s 150th anniversary.

Battersea Dogs & Cats Home, which is the country’s most renowned rescue centre, began life as the Temporary Home for Lost and Starving Dogs in Holloway, North London, back in 1860. To celebrate its 150th anniversary, the rescue centre has teamed up with Royal Mail to create the perfect set of stamps for pet lovers.

We normally see the pictures of dinasours with very dull body colors, but you can see something different here. The scientists had decoded the world’s first full-body color pattern dinasour. It’s a 155-million-year-old Anchiornis huxleyi, a kind of small-size beastly-foot class dinosaurs.

Here are some funny pictures of cute animals to make you smile so that you will be happier and have less wrinkles.

“Being a mechanic is hard work, but it pays the bills and feeds the kids!”