Jigglypuff (SSB4)/Side special/Default
Jigglypuff punches forward, slowly sliding along the ground as it does so. When used in the air, it quickly jolts forward a short distance, and moves forward a smaller distance overall, but can be angled up or down slightly. The move is a significant asset to Jigglypuff's neutral and spacing game, as well as its offensive game, and potentially its recovery. It's somewhat disjointed and long reaching hitbox makes it difficult to trade with, resulting in it being useful for approaching opponents, as well as walling them out. Furthermore when angled downwards, Jigglypuff can move from just above the reach of its opponents to within range for the hitbox to connect, potentially allowing it to be used as a spacing and neutral tool as well. It deals 11% damage, and has decent knockback, albeit rarely enough to KO. Finally, the move has an additional 20 shield damage, allowing it to take out around 70% of a shield's health, and as such can be used to break shields that have already sustained some damage, which combined with Rest's impressive KO power provides Jigglypuff with a potentially deadly shield pressuring option.
However the move suffers from some flaws as well. Firstly, the move has 12 frames of startup lag, and a duration of 45 frames, making its usage somewhat of a commitment. Additionally, as mentioned before it does not have the ability to break shields until they have lost more than a quarter of their maximum health, which combined with the fast shield regeneration speed in SSB4 somewhat hinders its ability to be used on shields. Finally, unlike in previous games where it can be used very effectively for recovery, the move actually somewhat worsens Jigglypuff's recovery if not utilized frame perfectly, and furthermore slows down Jigglypuff's recovery significantly, potentially leaving it open for edgeguarding.
Overall, while it does have some weaknesses, its rather pronounced strengths make it a solid part of Jigglypuff's moveset, as well as its safest and least situational special move.