If something is slippy, it is smooth and wet, so it is easy to slide on.
Slippy things can be dangerous because you might fall on them.
Examples:
The floor is slippy after it rains.
Be careful, the road is slippy when it's icy.
I don't like slippy floors.
The slippy slide at the park is so fun!
The slippy ice made it hard to walk.
The slippy banana peel made him fall down.