Why is this cat laughing? Well, it comes down to this: He's got a dead warthog behind him, he is the fastest creature in the world, and he just scared the bejeezus out of a bunch of American tourists. So, it's a pretty good cheetah day. The clues to a cheetah are its body size (usually smaller than a leopard), the spots as opposed to rosettes on the pelt, and finally as several of you pointed out, the vertical lines on the medial face. Although the reality is they are very risk avoidant (their bones are too fragile to go head-to-head with other predators) and will usually run from a fight, this guy put on a pretty good bluff for us.
So, on to the quest for (medical) knowledge! Enjoy this month, I will be serving up some tasty diagnostic dilemmas. Sur la planche!