The only way to get Black Sludge is to take it from wild Croagunk or wild Toxicroak. These are the only two Pokémon you can find holding the item, and they each have a 5% chance of holding a Black Sludge with every counter.
- Wild Croagunk are found on Route 212 and in Pastoria City’s Great Marsh
- Wild Toxicroak are also found in the Great Marsh, but only after you receive the National Pokédex.
The Black Sludge is a held item that replenishes a small amount of HP to a Poison-type holder at the end of every turn. Any non-Poison types that hold it will suffer the effects of poison instead.
Acquiring Black Sludges
Every Croagunk and Toxicroak you encounter in the wild has a chance of carrying a Black Sludge as its held item.
Of the two Pokémon, Croagunk is the easiest to find, so that’s what we’d recommend farming.
Here is a table of all of their locations:
The likelihood that either Pokémon will be holding a Black Sludge is 5%. However, you can vastly raise the odds by putting together a dedicated item-farming team that uses the Abilities Compoundeyes and Frisk to make the process much faster.
When you’ve found a Pokémon holding the Black Sludge, either catch it, or use a stealing move like Thief or Trick to obtain the item.
Then you can end the battle however you prefer; you’ll hold on to the item even if you flee.
What Does the Black Sludge Do?
The Black Sludge is a held item that heals a Poison-type Pokémon by 1/16 (6.25%) of its maximum HP at the end of every turn. If a non-Poison Pokémon holds the item, it will instead be damaged by the same amount.
On Poison-type Pokémon, the Black Sludge has the same effect as the Leftovers, which is one of the most popular items in the series.
But the Black Sludge has another benefit too:
If it gets stolen from you by a non-Poison foe using Trick or Switcheroo, your opponent will begin taking steady damage. And they’ll either need to waste a turn switching the item back to you or continue suffering until the battle’s over.