Danny Zuko and Sandy? What are they?

https://www.youtube.com/watch?v=ZW0DfsCzfq4

https://www.youtube.com/watch?v=x0q2x_8zvcY

https://www.youtube.com/watch?v=wsQJVAzezrc

https://www.youtube.com/watch?v=7oKPYe53h78