I have watched some films recently, and they are full of weird mistakes. A bunch of balloons can't lift your house into the air. DeLoreans can't actually travel through time. Gamma rays don't give you superhuman strength. A 6502 CPU couldn't power an advanced AI for killer robots from the future. So unrealistic.

Was my first reaction too when seeing the video at the top. But then after thinking about it, it makes sense as an example, you want to showcase things that aren't real but look realistic. A hippo swimming looks real, but it isn't as they don't swim.

Haha, this is the first thing I thought of too. I knew adult hippos walk on the bottom, but from looking at existing videos it looks like small (baby/pygmy) hippos do too, they don't float at the surface like this.