Humans in Australia deal with kangaroos daily in a mostly peaceful way, so this video is odd in the sense that the kangaroo is the aggressor in this attack. You'll see the man try to defend himself...but the roo is not put off...just keep up the beating.
CAUTION: ROUGH LAUNGUAGE. In 2016 the video below caught this rare fight. A man rescuing his dog had to punch a kangaroo in the head.