One of the animals they had there was the rhino. I think they were in season, because one of the rhinos seemed pleased to see another, while we were there. Hung like a horse wouldn't describe it. I think one of the kids at the zoo described it best when she asked "Why has that rhino got three legs at the back?" Her Mum wasn't too sure how to answer, saying "I'm not too sure, now I think we should go," suspecting something worse might come next. It didn't, but you can understand why she was worried.
One that note, I think I'm jinxed. I took the family to see a bunch of zoos over the years, and it first happened at a petting zoo. Two horses were getting down and dirty. Over the years since, we've saw Buffaloes, Lions, Sheep, Bears, Giraffes, Elephants and Giant Turtles, feeling frisky as it were. It even became a bit of joke. Bets being taken as to what we'd find. As often as not, nothing was found, but whenever we'd get there, they'd go hairing round to see if any of the animals were doing the do, before reassembling near the entrance.
It was horribly inappropriate, I know, but it kept them involved.