Spiny

Spinies are quadrupedal Koopas with oversized, spiky shells. Way back in the days of Super Mario Bros, Spinies could be found when thrown by a Lakitu or, less commonly, by themselves. Tricky part is, they can't be stomped and must be defeated by fireballs. This pattern continued in the same way until Super Mario Bros 3, when Spinies that walk on ceilings were introduced. When Mario passes beneath them, they drop and start shell-spinning. Ceiling Spinies came back in New Super Mario Bros Wii, where their upside-down shells (once dropped from the ceiling) could be stomped and carried because the spikes are facing down. Spinies appeared in many games between, but they never change their attacks except for Super Mario Galaxy 2. Here, they charge toward Mario if he approaches, but a tongue-slap from Yoshi can send them into their shells. Yoshi can then swallow the shells and spit them out as projectiles.