Mom's assassin. Luffy and the Seducing Woods!:
The strange things come one after another in this forest, just after crossing with Luffy's double, the crew meets with a huge person who is half buried. Right then, they are attacked by Randolph, one of the henchmen of the pirate Big Mom. The group tries to flee from the forest, but soon they discover that they are only running in circles, since they always end up in the same place. It's then when Nami realizes that the Luffy that accompanies them is not the real one, it is an illusion created by Brûlée, Big Mom's eighth daughter.
Download this episode from here.