is one piece episode 84 filler?

Nami finds herself surprised, as the strange creature she met when she woke up is able to talk. It appears to be worried about her health, but acts scared and clumsy.

Dr. Kureha calls him Chopper.

She informs Nami, whose fever has gone down, that her sickness was caused by a disease-carrying bug-bite and that it would have killed her in two more days. Because of the severity of her sickness, Kureha tells Nami she has to stay for at least three more days in order to recover.

In the meantime, Chopper looks after Luffy and Sanji in another room.