Dream Ball is an item in the “Special balls” category (Poké Balls).
In-game descriptions
| Black / White · Black 2 / White 2 | A special Poké Ball that appears out of nowhere in a bag at the Entree Forest. It can catch any Pokémon. |
|---|---|
| X / Y · Sun / Moon · Ultra Sun / Ultra Moon · Let’s Go, Pikachu! / Let’s Go, Eevee! | A special Poké Ball that appears in your Bag out of nowhere in the Entree Forest. It can catch any Pokémon. |
| Sword / Shield | A somewhat different Poké Ball that makes it easier to catch wild Pokémon while they’re asleep. |
Where to find it
Not placed on the atlas maps (so far: Red/Blue and Generation 3).
Sources : PokeAPI (items, item_flavor_text, machines) · atlas · pokeemerald species_info.h