BoBoiBoy Thorn is the evolved form of BoBoiBoy Leaf. He was a minor character that made his debut in BoBoiBoy: The Movie as one of BoBoiBoy's new elemental forms. He is slated to appear in BoBoiBoy Galaxy.
When Ochobot was destroyed and gave BoBoiBoy the last of his powers, BoBoiBoy summoned Thorn, along with all the other forms in a blind rage.
His appearance is somewhat the same as the other forms of BoBoiBoy with cropped black hair and the regular physique of a child, but BoBoiBoy Thorn possesses green irises and is clad in mostly green and black with his cap being fully black with a minor addition of neon green vine-like linings adorning the sides of his cap all the way to the bill. He wears the said cap with the bill turned to the left of his head. Unlike the other elemental split personas, BoBoiBoy Thorn does not appear to sport a jacket but instead, he wears a short sleeved shirt with black coloring the upper part and green on the lower part of the shirt, with green pants adorned with black jagged, thorn-like linings at the sides. His shoes are a mix of green and black colors laced with white shoelaces. His insignia is placed at the front of his shirt, right under the hoodie. Accessories that mainly differentiate him from the other forms happen to be the green thorn-like studs on a green wristband worn on his left wrist and a black arm warmer (adorned with green studs) that covers all the way from his right forearm to his hand.
Being the evolved form of Leaf, Thorn has similar and evolved abilities that Leaf has.
- Ensnaring Thorns (Akar Berduri) - This attacking power consists of thorny vines, lengthened to desire. It holds the purpose of binding one to place thus immobile them.
- Thorn whip slash - This is used for his primary attack
- Alongside BoBoiBoy Solar, Thorn is the one of the only two elements where BoBoiBoy did not need the base form (in this case Leaf) to use that form.
- BoBoiBoy apparently looses the ability to use this form in the events of Galaxy, but Thorn's base form, Leaf, appears in Episode 5, hinting that Thorn may appear in the future.