- “Do not touch the thorns. They will knock you out! You can destroy the thorns by hitting them with eggs.”
- —Message Block in The Potted Ghost's Castle, Super Mario World 2: Yoshi's Island
Thorns, also referred to as crystals, spike blocks, or simply spikes, are spiky obstacles found in Super Mario World 2: Yoshi's Island (and its reissue), Yoshi's Island DS, and Yoshi's New Island. They are found mostly in castles. If a Yoshi touches a thorn, he will immediately lose a life. A Yoshi Egg destroys a single thorn, but since thorns are found usually in groups and a Yoshi can carry only six Yoshi Eggs at a time, most thorn groups are impossible to destroy. However, in Yoshi's Island DS, Baby Donkey Kong's explosive eggs can easily destroy a group of them in one shot. Sometimes, after they are destroyed, the thorns reveal Winged Clouds, and in The Potted Ghost's Castle, one specific thorn reveals even a door.
Names in other languages
|A Japanese term meaning "spiky"; shared with an object from Wario Land 4|
- Williams, Drew. Yoshi's Island: Super Mario Advance 3 Player's Guide. Page 51.
- Williams, Drew. Yoshi's Island DS Player's Guide. Page 30.
- Black, Fletcher. Yoshi's Island DS PRIMA Official Game Guide. Page 74.
- 「任天堂公式ガイドブック ヨッシーアイランドDS」 (Nintendo Kōshiki Guidebook - Yoshi's Island DS), page 51.
- 「任天堂公式ガイドブック ヨッシー New アイランド」 (Nintendo Kōshiki Guidebook – Yoshi's New Island), page 106.
- 「任天堂公式ガイドブック ヨッシー New アイランド」 (Nintendo Kōshiki Guidebook – Yoshi's New Island), page 174.