If it is a possum it is harmless to people and actually helps our environment by eating insects and other things. Just leave it alone and you'll be fine. There is no reason to kill something because it isn't pretty.

It is definitely not a possum! Have a closer look the picture if that is possible.
It is a metal thing which is in the floor, and it made me almost fall twice.

Perhaps you could have described it a little better in your post. The photo is of very poor quality but it seems large enough to be seen while walking if paying attention.

Sorry about that, I didn't know how to describe this. I think the photo got downsized when uploading it. I can take an other picture when I am in the area.

I didn't see it twice on my side, but maybe other people pay more attention to it. I would say it has a size 3'' x 3'' and a height of 4''