”You can just teach them toxic in generation seven and then move them up to gen eight. If you're on Pokemon showdown then it doesn't matter as these Pokemon can still use toxic”
commented 10 hours ago by Demon Hunter
This is correct. Alternatively, you could try some of these:
Foul Play
Foul Play will deal damage based on the opponent’s attack, as well as having nice power. This can help against strong physical attackers for Pokémon that don’t have good attacking stats.
Thunder Wave
Thunder wave is good for crippling opponents, as it halves the opponent’s speed and makes them have a 25% chance of not moving. It doesn’t do damage, but it sure is annoying.
Will-O-Wisp
This one is a good one. It halves the damage of the opponent’s physical attacks, as well as dealing gradual damage. Unfortunately, this won’t do well against special attackers, so it’s better to use this on a special defender.
Leech Seed
It deals a good bit of damage every turn, AND heals you. This one is amazing, but sadly is nearly exclusive to grass types, which aren’t usually the best defensively (besides Ferrothorn).
Seismic Toss/Night Shade
These deal damage based on level, not attacking stats, so it’s good for defenders with bad attacking stats.
Body Press
Body Press deals damage based on Defense, not attack. This is quite helpful on Physical defenders with high defense stats.
Toxic Spikes
These can poison/badly poison things that are grounded and switch in, which is deadly (and annoying).