"You've earned the Mallarchy Pond Mega Winner achievement!" Unlocked Mallarchy Pond Mega Winner! Win the grand prize at the Mallarchy Pond!

How does it differ from winning 1st place? I won nothing but 5 Carnival Tickets for picking the winning duck. Where is my "Grand Prize"?

I'm not sure what happens now that they've changed to tickets. You used to get the background:

I would submit a ticket and ask about it. Point out that there are 3 achievements, one for playing several games (Mallarchy Pond Player), one for picking a first place (Mallarchy Pond Winner) and for the mega winner (Mallarchy Pond Mega Winner).

I'm not sure if there is more that pond dirt clump, that's the one I won. There may be others.

[edit] Oh...that's interesting. When you hover over the Pond Dirt Clump, it shows a price of 30. Seems to me they intended to add it to the carnival shop, but it doesn't show up there. Highest priced items are 25 tickets.

Thank you for your explanation!