From the Super Mario Wiki
Retrieved from "https://www.mariowiki.com/index.php?title=Kurasshā&oldid=2240177"
Kurasshā are stone blocks debuting in Donkey Kong for the Game Boy as tough, indestructible obstacles. They first appear in stage 2-8, on the Forest, and behave just like Thwomps, despite showing no signs of eyes or facial features. If Mario approaches them, they drop down and attempt to squish him. If they do so, Mario becomes surrealistically flat and loses a life. On the other hand, Mario can hop on and use them as improvised elevators. In this instance, Kurasshā can squish Mario by pushing him against the ceiling.
Kurasshā return in Mario vs. Donkey Kong, where they act almost exactly like they did in Donkey Kong. In this game, they keep smashing the ground regardless if Mario is below them; their original exact behavior was passed on to actual Thwomps.
Names in other languages