In the rare moment I think of Donkeys at all, I sometimes confuse them with Mules. I think one of those is a sterile hybrid, and cannot reproduce. Similar to a Dolphin and a Porpoise. Aren’t they the same thing? ///
Easy mistake. A mule is a cross between a donkey and a horse. Mules are larger, stronger, more stubborn, hardier than donkeys, but less friendly and less tolerant.
The easiest way to tell a dolphin from a porpoise is that dolphins muzzles stick out like beaks.
Difference between dolphins and porpoises -
https://oceanservice.noaa.gov/facts/dolphin_porpoise.html