Big is a comparable adjective, since it can take the forms bigger and biggest; but unique is not comparable, except in disputed, but common, usage.

I cannot be fanwanked past the point that Chewie and Leia not acknowledging each other as he got off the Falcon was a fairly large mistake.

IF we can believe our old, wise searchers or investigators, the Dachshund belonged to the oldest breed of dogs known in ancient times.[…]Since the Sixteenth Century German literature speaks of the Dachshunde, although they are described differently at times, as, for instance, the “little earth dog or hole dog.”

PROPOSITION IV. That axiom of metaphysicians which is termed the principle of contradiction, and which affirms that it is impossible for any being to possess a quality, and at the same time not to possess it, is a consequence of the fundamental law of thought, whose expression is x² = x.