Can a Hippo walk backwards ? I don't mean like back up a little - but
actually walk backwards.

I would like to suggest that NO four-legged animal can (or would) walk
backwards (except to 'back up a little').

They only look stupid.

may be it jumps backward

About hippos, I have no idea.  But I know I've definitely seen horses
walk backwards for at least 20 or 30 feet.  Granted, this was a
trained police horse and I'm not sure about what they would o in the
wild....but they certainly have the capacity to walk backwards.

Yes, Andrewxmp .... A trained police horse OK and maybe a trained
whatever at some circus ...

But would any untrained animal choose to walk backward?

Animals do like to see where they are going.

Even people ... check things out today and report back tomorrow how
many people you see walking backwards FROM CHOICE. (People helping to
push or carry things; or negotiate steps, etc. excepted.)

Hmm. Interesting points.

However I'd suggest that while four legged animals wouldn't enjoy
walking backwards, and thus would be unlikely to do so, the same would
apply to two legged animals like us.

We don't. But we can.

i think they can--other 4 legged animals can i.e.--dogs, cats, lions,
tigers, why wouldnt a hippy b able to?