Swampy Mega Ducks are a variant of Mystery Ducks which appear in Mystery Duck Challenges.
- Swampy Mega Ducks 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 a Swampy Mega Duck and completes the challenge, it is added to the Mystery Duck counter (A Swampy Mega Duck counts as one Mystery Duck). For every three Mystery Ducks collected, a new Duckie costume is unlocked.
- Swampy Mega Ducks require twenty drops of Water to fill and collect. All other Fluids, except Steam will kill Swampy Mega Ducks. If the Swampy Mega Duck is killed or if the level is completed without it 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 Mega Duck.
- While Full, the Swampy Mega Duck takes on the appearance of a full Swampy Duck albeit much larger, though with a smaller head, beak and eyes compared to its body.
- While Empty, the Swampy Mega Duck has the shape and features as his full version, though in shades of orange.