WHO IS, THE BUIGGEST FURRY IN EaGLETiM E,??? ?

Incorrect, PM is definitely taller than Jacquerel, a fact which I would expect you of all people to already know.

Spoilered on the off chance that anyone still cares about homestuck spoilers:

SpoilerShow

No word on whether Davepeta is taller or shorter than PM, but PM is clearly taller than Dave Prime, as can be seen in above picture.

But this is all beside the point though because the biggest furry in homestuck is actually the Black King from the troll's session.