Stone Spike

Stone Spikes are a sub-species of Spikes that appear in New Super Mario Bros. Wii. They are blue in color and have green hair. They act like normal Spikes, but are found in mountainous regions and throw spiked balls made out of rock. They are found in some stages of World 6 and in World 8-4. Unlike normal Spikes, Rock Spikes can only throw their spiked balls downwards, rather than forwards or backwards. They can be defeated just like normal Spikes; by jumping on its head, by throwing a fireball at it or by freezing them using an Ice Flower or a Penguin Suit.

Trivia

 * Most likely by coincidence, their color scheme resembles both Tubba Blubba's, and Grubba's.
 * These are the only enemies (aside from Bloopers) that always face the player.