Twilight Thorns are bosses from Chain of Memories and Kingdom Hearts 2.
Twilight Thorns are giant Nobodies that attack with lightning-like thorns. They were controlled by Marluxia.
Only appears in Kingdom Hearts 2, when Roxas goes to the Station of Awakening. You can't attack it at first because it holds you up in the air with energy. You can defend and counter his first attack with reaction commands. You do the same thing with his other 2 attacks. If successful in your third counter, it will leave Roxas and Twilight Thorn on the ground. Roxas will get up first and get back the Keyblade. When he gets it back, you can start attacking Twilight Thorn's head. Then it will get up and start attacking and summoning Creepers. Use the reaction commands to avoid it's attacks.
Twilight Thorns have an interesting resemblance to Darkside. They may be related.