I am a huge fan of hippos, and I think they are the true king of beasts. Those giant teeth, crushing jaws, surprisingly quick top speed, equally dangerous on land and water, and one of the few animals that will go after humans, they are very intimidating animals.
With that said, I did get to boop a hippo, and that is one of my favorite accomplishments ever. I thought it felt like a giant strawberry. Leathery, but smooth, and the little dimples where the whiskers come out reminded me of the seeds.
Their enclosure behind the scenes of their exhibit looked straight out of Jurassic Park, with 4" steel bars on everything and all types of mechanical gates. I also got to feed them, and it was like throwing food down a huge garbage shoot. It was fun in that scenario, but if those huge bars weren't there, that would be quite the terrifying last sight.