An 18kg deer at a zoo in Poland woke up one morning, looked at himself in the mirror, and decided it was time to square off with a 1.7-tonne rhino to finally show the big creature who’s the boss.

In a video shared by the Wroclaw Zoo on Jan 8, a Chinese muntjac deer can be seen charging a hulking rhino with the confidence of someone who has either misplaced his sense of scale or discovered a surplus of testosterone.