Swampy Ducklings are a variant of Mystery Duck which appear in Mystery Duck Challenges.
- Swampy Ducklings are found in some Mystery Duck challenges. A new Mystery Duck challenge appears every 24 hours, but a different type of Mystery Duck will likely feature.
- When a player collects ten Swampy Ducklings and completes the challenge, it is added to the Mystery Duck counter (Ten Swampy Ducklings counts as one Mystery Duck). For every three Mystery Ducks collected, a new Duckie costume is unlocked.
- Swampy Ducklings require one drop of Water each to collect and fill (ten total). All other Fluids, except Steam will kill Swampy Ducklings. If one of the ten Swampy Ducklings is killed or if the level is completed without them all being collected, the level fails.
- Once all Duckies that are unlocked with the Mystery Duck are unlocked, Mystery Duck challenges will no longer appear, thus, neither will the Swampy Duckling.
- While Full, Swampy Ducklings take on the appearance of a full Swampy Duck albeit much smaller, though with a larger head and eyes compared to its body.
- While Empty, Swampy Ducklings have the shape and features as his full version, though in shades of orange.