Rest

Rest, known in Japan as Sleep, is 's down special move in Super Smash Flash 2.

Overview
When performed, Jigglypuff falls asleep for a little while before waking up. The move has no effect on opponents if Jigglypuff is out of proximity with them, but if Jigglypuff uses Rest while an opponent is in contact with it, the opponent will be dealt 18% damage and launched with extremely high velocity and knockback. The attack comes out in and lasts for one frame, and in that one frame, Jigglypuff will have invincibility as well. The attack's hitbox consists of Jigglypuff's body, and the hit contains many freeze frames.

Rest is one of Jigglypuff's most potent moves, and one of the most powerful moves in the game. This is due to the fact that it deals very high damage and knockback, being able to KO reliably at low percentages. However, it is also Jigglypuff's riskiest move due to its extremely high ending lag, allowing either for opponents to easily punish or for Jigglypuff to fall into the bottom blast line when used off-stage, as well as its relatively small hitbox that can often miss opponents.

Spacie slayer
The spacie slayer is a combo that can be performed by Jigglypuff against fast-fallers like, , (although due to his slim sprite hurtbox makes it difficult to connect with), and  due to their very high accelerated falling speed. High fallers like, , , and more are also susceptible to this, but they can escape it a little easier due to their accelerated falling speed being lower. How this works is that Jigglypuff takes advantage of a character's accelerated falling speed and is able to combo into Rest by using its up throw, up aerial, or up tilt. However, there is no guarantee that the opponent will be hit by Rest due to them being able to DI away from Jigglypuff, but due to Jigglypuff's high air speed, this normally should not be a problem.

This technique is very risky to do because if Rest is missed, Jigglypuff will be left open to be punished. Even if Rest hits, the opponent may have a chance to recover if their damage is low enough. Also, it is best to use this technique on fast-fallers on stages with a high platform such as or Yoshi's Story, as the top platform being there would allow for the opponent to land on it and lie down, which forces them to tech or use their floor attack. This gives the player enough time to predict what they are about to do and follow up with a Rest.

Origin
Rest is a Psychic-type status move in the Pokémon games that was introduced in Generation I with Pokémon Red and Blue. Nearly every Pokémon can learn Rest via TM44, but Jigglypuff is one of the few Pokémon that can learn Rest by leveling up. However, the  version of Rest and its SSF2 counterpart are completely different from the Pokémon version. In Pokémon, Rest does not do damage to opponents; instead, it puts the user to sleep for two turns in exchange for recovering all of their HP back to maximum and healing any status ailments. The two turns of sleep may leave the user open to their opponent's attacks or setup, unless the user has an item or Ability that can cure the sleep early.

In SSF2, Rest also puts the user to sleep and leaves it vulnerable in exchange for a powerful effect, but instead of healing damage, it deals damage with very powerful knockback if used right next to an opponent. In the description of one of its Super Smash Bros. Melee Smash trophies, as well as in Solid Snake's Codec Conversation about Jigglypuff in Super Smash Bros. Brawl, it is stated that this is because at the instant Jigglypuff falls asleep, a huge buildup of energy forms at the center of its body. This is an example of the Super Smash Bros. producers changing the functions of a move to suit the games.