This was the cute moment a young hippo calf and its father were play fighting in a river in South Africa's Kruger National Park.
The footage shows the wide-jawed beasts biting and nudging each other.
The filmer said: "While stopping on the banks of a river, we spotted this large male Hippo interacting with a young little hippo.
"At first glance, it looked like a fight that could get serious.
"While paying attention to the behaviour, it quickly became clear that this was not a fight.
"More a Father hippo teaching a younger male how to show off dominance.
"This is a huge part of a male hippo’s life.
"Big monster like yawns are a sign of dominance, showing off size plus those large and ever-dangerous bottom tusks.
"Male hippos are Africa’s most dangerous and aggressive mammals alive, killing more people than any other.
"Male hippo’s also do fight a lot with other males which many times lead to death.
"These fights are brutal, so as a young male hippo, you better learn quickly how to display those monster yawns and show dominance.
"It’s tough out there and you need to be prepared.
"At the end of the video the youngster got terrified by the last huge yawn and got himself out of there quickly."