For instance, this rat snake showed up a few weeks ago and scared my wife. It's welcome to stay around the yard and eat all the mice it wants, as long as it stays out of the house. It's a scary creature, but basically harmless to humans.
These little green lizards are also common in my yard. I love them and want to see more of them. They feast on all the insects that are common because I don't spray insecticide. It's quite enjoyable to sit in a chair outside and watch the lizards skitter around.
Plenty of other critters occasionally show up. Having our own little wildlife refuge brings great educational opportunities to our homeschooling family and makes everyday life interesting around our home.