it may be useful to explore some of the symbolic relationships of the things you saw in your dream. First, go through the series of events in as much detail as you can. What was the monster? Were there any aspects of it that felt familiar? Did it say or do anything that jumps out in your memories? What about the cats. Were they regular cats, great cats (like lions etc), a mix of both? Where did this happen. are there any memories of the setting. In a building, in a forest, in city streets? Were you alone or were there others with you? Were they people you know or knew?
Asking yourself these questions helps you so look for the extra little details that might add context to the dream, or otherwise give you some sort of breadcrumb trail to follow and lead you to a clearer picture of the dream.
Once you have as much detail as you can recall, go through the bits and pieces one step at a time. Maybe examine the role of cats in symbolism both in relation to the deities or practices you follow, and as totemic symbols. Do the same thing for the different stand-out features of the monster.
Usually in dreams monsters are built out of the things that currently frighten you or make you feel without power and vulnerable. if you can tie the monster to something that is currently going on in your life that will give a huge dose of context to relate the rest to.
And finally, remember to sit back for a minute. take a breath, take a rest, have a nibble of something comforting, and remember that there are also some times when a dream is just a dream. A random story fear generated by a random idea written by your brain around a random 'Hey I wonder if..." and seeing where the curiosity takes you. So remember to relax. Explore it with interest or curiosity, not out of fear or assumption. Doing so will only unnecessarily color what you interpret into what you are afraid it might mean... instead of what it actually could mean.