FYI, this a bad idea because Hippos are not cute placid animals. They are deadly dangerous. They may be herbivorous, but a Hippo is two tons of bad-tempered "aggressive and territorial" bastard, and they can move faster than you can, on land or in the water.
"the hippopotamus is the world's deadliest large land mammal, killing an estimated 500 people per year
"the hippopotamus is the world's deadliest large land mammal, killing an estimated 500 people per year
https://www.bbc.co.uk/news/world-36320744