In my dream I am walking in the country and saw a lady with a huge
alligator/crocodile. She say he is very old, 237 years, and will make a
monument/memorial when dies. I can touch the alligator's foot and do not feel threatened. What does this mean? Can you give me advise? Thank you.

Here's a link to the definition of an alligator in a dream: dreamdoctor.com/dream-dictionary/definitions/alligator.html It should help you ID who it is (probably male) in your waking life. The lady should provide a clue. As for why 237 years old, numbers in dreams may or may not have a meaning. If there is a meaning, it's likely to be something that has relevance for you only, unless it's a number like 9/11 or 911. Here's a link to the definition of a number in a dream: dreamdoctor.com/dream-dictionary/definitions/number.html . In the case of your dream, it may just be a number that communicates to you that the alligator/person is really old.

Hope that helps!

Thank you so much! In your experience, could this person be someone from past life?

The short answer is "no." Dreams are expressions of your feelings about what is most important to you in your waking life at the time of the dream. If you extend your search to possible past lives, psychic phenomenon or astral planes, you are likely to miss a truth which is much more logical and obvious.

Good luck!