Unusual garden visitors- have you had any?

I’ve just returned from a visit to family in Australia and a couple of times we stopped on the road while an echidna crossed, although they were quite small. I was upset to see so many dead possums by the side of the road - on their backs with their little legs in the air. I asked why you often see those and dead kangaroos with red crosses painted on them and I was told it’s when their pouches have been checked to see whether there’s a baby to be rescued.