According to a statement by Miyamoto at the Super Mario Bros. 30th Anniversary festival in September 2015, Mario's last name is also Mario (Mario Mario).

Wart from Super Mario Bros. 2. Now, yes ... and maybe a Rabbid would be in the background or possibly even referenced somehow ...

As we sit down to write this review, there’s a temptation – one that Nintendo has perhaps anticipated and therefore wisely forbidden us from giving in to – to simply list all of the completely bonkers ...