Rhomp

Rhomps are enemies that appeared in Super Mario Galaxy 2. They are rare enemies that only appeared on the sand slide in Slipsand Galaxy. Their attack is trying to flatten Mario. They are cylinder-shaped stones that have smiley faces carved into them. They look similar to Spindels, with even the same attack, but have no eyebrows and no wrappings around them.

Trivia
Rhomp is a portmanteau of "roll", referring to the enemy's attack, and "Thwomp", a related enemy.