Anywhere where a king has a cat. If the cat is not blind then he can see the king.

I would say that "A cat can look at a king " is a proverb. It means that no one is so important that an ordinary person cannot look at him or her. Everyone can be curious about important people. Also cats are known for doing whatever they please.

It means something like "ordinary, common, average people (cats) are capable of great things and deserve all the best (like kings)".

Only when you're on drugs.

I've probably placed this comment in the wrong box - but in my area Jura would be right. If you happen to look at someone who is in a bit of a bristly mood he/she might say "What are YOU looking at?" and the phrase "A cat can look at a king" is used to stand your ground in the face of this sour reaction, but not too offensively - although the inference in the use of the word king is that this person's attitude is a bit too high and mighty