A seed is planted on the target. It steals some HP from the target every turn.

Gen 1 move. Drains 1/8 of the target's HP at the end of each turn.
(search how it interacts because it keeps sapping pokémon even if the user switches out etc)
Fails when used on a Grass-type Pokémon. A Grass-type can be affected by Leech Seed if the effect is passed onto it through Baton Pass.