From the Super Mario Wiki
While the game can generate Tornado Spear-Masks depending on difficulty, Wario can turn Spear-Masks into Tornado Spear-Masks by Ground Pounding once. Ground Pounding when a Tornado Spear-Mask is present will transform them into Angry Spear-Masks.
Tornado Spear-Masks function much like ordinary Spear-Masks. However, as their name suggests, once they turn around, they spin their spears (creating a "tornado"), damaging Wario if he touches them while they spin their spear. Defeating them yields better rewards compared to the Spear-Mask, but not as much as an Angry Spear-Mask.
They resemble Shy Guys since both have similar body shapes and clothing.