Forest, a 12-year old giraffe who hasn't stopped growing, but is already too big to fit in the picture above, has been certified by the Guinness Book of World Records as the tallest living giraffe—and therefore, by default, the tallest living animal.
At 5.7 metres, Forest is a bit past the height of a two-story building. He is at the Australia Zoo, owned by the family of the late 'Crocodile Hunter' Steve Irwin.
In their natural environment, giraffes are considered a 'vulnerable' species, and Forest is part of a breeding project at the zoo. He's the father of twelve calves and is expecting a thirteenth soon.