No one is born knowing that cats can be rather temperamental playmates. Indeed, that's a bit of knowledge that often must be learned from scratch - or scratches.
This kangaroo, for example, recently got an unforgettable lesson on the fickleness of felines. In a video uploaded to YouTube, the friendly 'roo named Hop is seen simply trying his best to cozy up to a napping cat, offering a few friendly head pats, when things suddenly get a little nasty.
The cat basically loses his chill.