According to the wiki page on Trebol, he should be a Logia user, using the Sticky Fruit's powers. This was verified in chapters 741 and 760, when we could see Trebol completely unaffected after being cut into pieces by Usopp and Law. Now chapter 782 makes me really confused.
In chapter 782, we could see how he was hit by Luffy, yet remained completely unharmed despite being hit with hardening Haki. Logia users should be hurt by attacks like these. Additionally, later in the chapter we can see Law cut his body open with his sword. This could be defended by the fact that Law could have imbued the sword with Haki, but the appearance of Trebol's shriveled up old body, makes me really think Trebol was Paramecia after all. Although a Paramecia should not have been able to live after having his body severed. Now what's the deal here?