Thunder Wave

TM05

Toxic

TM07

Transform

Toxic badly poisons the enemy. No immediate damage occurs; however, on its next turn to attack the victim suffers damage equal to that caused by the normal PSN status-change: 1/16 of its maximum HP. Let's call that value X. On the following turn, (this will be either the 2nd or 3rd turn since Toxic was used, depending on the relative Speed of the combatants) the damage increases to 2X. The damage on the next turn will be 3X, and so on. This means that unless the victim has some method of healing itself, or the Toxic effect is somehow removed (see below), a Toxicked Pokémon can last a maximum of 7 turns before fainting, regardless of its stats.

This damage progression, and the interaction between Toxic and certain other attacks, are best explained by assuming the existence of a variable in the game that is checked each time recurrent damage is taken. We'll call this variable R: it ordinarily has a value of 1, and it is multiplied by 1/16 of the victim's maximum HP value to produce the amount of recurrent damage. One effect of Toxic is simply to PSN the victim, but another is to flip R into cumulative mode. When this happens, each instance of recurrent damage increases R by 1.

If a Toxicked Pokémon is switched out of battle, or if the battle ends while it is still alive, R is reset to 1 and becomes non-cumulative. That is, the Toxic victim will take only normal PSN damage (1/16 of max HP per turn) when it returns to battle.

Haze resets R and renders it non-cumulative. It will also remove the PSN status, but only if used by the Toxic victim's opponent: a Pokémon cannot change its own status by using Haze. Mist has no effect on R, whether used before or after Toxic.

Rest removes the PSN status, but does not reset R nor render it non-cumulative. Thus, if a Toxicked Pokémon uses Rest, it will regain all of its HP, and will no longer be poisoned. However, if it subsequently receives recurrent damage, either from the BRN or normal PSN status changes, or from Leech Seed, the damage done will be based on the current value of R. Also, R will still be in cumulative mode: the damage will increase with each turn. However, a second use of Toxic against a Pokémon that has Rested will reset R to 1, though it will remain cumulative.

The opponent's use of defensive attacks such as Light Screen, Harden, and the defensive aspect of Amnesia, and/or offensive attacks such as Leer or the Special-lowering side effect of Psychic have absolutely no effect on the damage caused by this attack.

If Leech Seed is in effect simultaneously with Toxic, the damage it does and the damage it restores to your Pokémon are based on the current value of R. For example, suppose that your Pokémon uses Toxic on the enemy, and then uses Leech Seed on the following round. Recurrent damage will occur according to the following progression. (This example assumes that your Pokémon is faster than its enemy):

Round 1
Toxic is used.
Toxic removes 1/16 max HP; R becomes 2.

Round 2
Leech Seed is used.
Toxic removes 2/16 max HP; R becomes 3.
Leech Seed removes 3/16 max HP; R becomes 4.

Round 3
Toxic removes 4/16 max HP; R becomes 5.
Leech Seed removes 5/16 max HP; R becomes 6.

Round 4
Toxic removes 6/16 max HP; R becomes 7.

Unless the victim switches away, uses a healing move, or becomes subject to Haze, it will faint at this point.

It should be noted that the greatest damage in the least amount of time will be achieved by using Toxic before Leech Seed. Consider this alternate damage progression, which again assumes that your Pokémon is faster than its enemy:

Round 1
Leech Seed is used.
Leech Seed removes 1/16 max HP.

Round 2
Toxic is used.
Toxic removes 1/16 max HP; R becomes 2.
Leech Seed removes 2/16 max HP; R becomes 3.

Notice that in the first scenario, 6/16 of the victim's HP have been removed by the end of the 2nd round, whereas in the above situation, only 4/16 have been removed.

NONE.

All Pokémon (except for Caterpie, Metapod, Weedle, Kakuna, Magikarp, and Ditto) can learn this TM.

This TM is unique and can only be obtained by defeating Koga at the Fuchsia City Gym.