Piranha Plant (SSBU)/Up smash
Piranha Plant lunges upward for a large bite. Up smash provides significant utility in Piranha Plant's gameplay, as it serves as a very punishing anti-air with large disjoint, capable of beating out most landing aerials, and even low-profiles during the first hit, and has a total of 7 active hitbox frames. Combined with immense strength, 90 degree angle which makes DI have little effect over its kill potential, it can kill even the heaviest of fighters before 100%, when fresh. This also makes it a devastating read tool against rolls and short hop approaches as well, and up smash is capable of hitting the bottom platforms of Battlefield as well. It is also tied with down smash for Piranha Plant's fastest smash attack, at frame 12.
Despite immense strength, the move has a tendency to fail to connect, with its first hit. It typically happens especially when catching extended hurtboxes, or hitting smaller characters. This factor, combined with its very poor horizontal range, make up smash difficult to use against grounded opponents, as it is quite unreliable at times due to the first hit. Thus, the move is typically relegated as an anti-air option, with Piranha Plant's other smashes being used for grounded opponents.