Scissors is a giant, sentient pair of green scissors, hence its name.
During the battle, Scissors possesses two basic attacks. Its first attack has it use its blades to shove Paper Mario away, and for its second attack, it will perform the Safe Tee, using its handles as a Golf Club. Its primary gimmick is that Paper Mario has to time his attacks based on its movements. Specifically, he has to hit Scissors's handle to attack them safely, which means attacking with his hammer when Scissors sticks their blades (which have the cover) in the air, and attacking with jumps when its facing its blades downwards.
After you reduce its health bar below half, Scissors enters its second phase, which involves it shedding the covers on its blades. It will then charge up its next attack, which can break through your guard and cause an one-hit KO, though it can be dodged by jumping. Paper Mario has to find a way to freeze the boss with an Ice Vellumental, then swing the block around to damage them, then follow with a 1,000-Fold Arms Rush Attack. Defeating Scissors fixes up those who got cut up. Scissors has around 400 hit points.